Integral of fractional part of x from 0 to 4

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blackpenredpen

blackpenredpen

5 жыл бұрын

Integral of fractional part function,
check out integral of floor(x), • integral of floor of x...
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Пікірлер: 162
@Ynook
@Ynook 5 жыл бұрын
The general answer. after inegration, would be x/2. It is pretty visual. You get half of the difference between the boundaries.
@stephensimpson7794
@stephensimpson7794 5 жыл бұрын
Doesn't hold for non integer number x. 1.2 would be 0.5 plus 0.5*0.2*0.2 or 0.5 plus 0.02 for an area of 0.52 instead of 0.6
@Ynook
@Ynook 5 жыл бұрын
@@stephensimpson7794 You are right. It doesn't hold for non integers. Still, it is useful for big integer numbers.
@Ynook
@Ynook 5 жыл бұрын
@@stephensimpson7794 A more general form would be (x+{x}^2)/2
@stephensimpson7794
@stephensimpson7794 5 жыл бұрын
@UCKzO7twZ3T3PVQCv390Xr6Q looks messy and doesnt cover negatives and has a sigma and summa
@tylershepard4269
@tylershepard4269 5 жыл бұрын
I absolutely love your new intro! Thanks for a lot of great content.
@blackpenredpen
@blackpenredpen 5 жыл бұрын
Thank you!
@nikodempatrycjuszswiercz4064
@nikodempatrycjuszswiercz4064 5 жыл бұрын
General solutions are: floor(x)/2 + ({x}^2)/2 for the fractional part and (floor(x)*(floor(x) - 1))/2 + floor(x)*(x - floor(x)) for the floor function
@stephensimpson7794
@stephensimpson7794 5 жыл бұрын
This doesnt hold for negatives
@angelmendez-rivera351
@angelmendez-rivera351 5 жыл бұрын
Stephen Simpson Agreed. I actually posted the same solution to the floor Integral in the other video, and I took care to specify that x > 0 or x = 0
@stephensimpson7794
@stephensimpson7794 5 жыл бұрын
@@angelmendez-rivera351 or we go with floor(|x|)/2 + {|x|}({x} + {|x|}/2)
@stephensimpson7794
@stephensimpson7794 5 жыл бұрын
Thatd be for strictly negative For 0 to either we'd use area of trapezoidal height * b1+b2 / 2 getting 0 or 1 for positive or negative (|x|/x)(floor(|x|)/2 + (1/2){|x|}({x}+|floor(x)|-floor(|x|)))
@albertosoria6564
@albertosoria6564 5 жыл бұрын
It help me so much the graph thank you!
@thebloxxer22
@thebloxxer22 5 жыл бұрын
One thing I pulled from this: When dealing with a negative number inside a floor/ceiling function, you flip the function direction (floor->ceil, ceil->floor) and pull the negative out front. Is that a safe statement?
@WAMProducties
@WAMProducties 5 жыл бұрын
In synthesis, thats what we call a 'ramp' wave! a saw wave would be 1 - {x}
@blackpenredpen
@blackpenredpen 5 жыл бұрын
Wouter Damen Oh! I didn't know the name. Thanks
@WAMProducties
@WAMProducties 5 жыл бұрын
I don't think that's the official mathematical name though! In my calculus book I found what I would call a triangle wave being called a saw wave aswell.
@angelmendez-rivera351
@angelmendez-rivera351 5 жыл бұрын
Suppose we want to integrate {x} from arbitrary a to b. We want to split this into three integrals: from a to ceil(a), from ceil(a) to floor(b), and from floor(b) to b, since this makes the process much easier. The first Integral is simply [ceil(a) - a]*[1 - {a}]/2 = [ceil(a) - {a}ceil(a) - a + a{a}]/2 since this is just the area of a trapezoid. The second integral is simply [floor(b) - ceil(a)]/2 since it is half the area of the rectangle of height one, and the base is the difference of the boundaries. The third integral is {b}^2/2. Adding it all gives [{b}^2 + floor(b) - {a}ceil(a) - a(1 - {a})]/2. Equivalently, we can evaluate the first two integrals using the floor function only. The first may go from floor(a) to a, but this we will subtract from the total. This will give {a}^2/2. The second integral will then run from floor(a) to floor(b), and it will equal to [floor(b) - floor(a)]/2. So the total integral from a to b of {x} is simply [{b}^2 + floor(b) - {a}^2 - floor(a)]/2. If we ever want to integrate {f(x)} from a to b instead, then we let u = f(x) so that dx = u’*(f^-1)’(u) du, with the lower bound u = f(a) and the upper bound u = f(b). Then you can perform a very similar decomposition of the integrals into three parts, but the middle integral with the second approach will be much harder to do now that we have extra-factors in the integrand. So instead we split this middle integrals, the first of the many going from floor(f(a)) to floor(f(a)) + 1, the second going from floor(f(a)) + 1 to floor(f(a)) + 2, so on and so forth until the integral that goes floor(f(b)) - 1 to floor(f(b)). And then you replace {u} with u - floor(f(a)) - n, and this you perform the integration. Or, one can also recur to simply doing {f(x)} = f(x) - floor[f(x)], but only if it is simpler. Now suppose we want to integrate floor(x) from arbitrary a to b. Then we can split this into separate integrals as well. We subtract the integral from floor(a) to a from the total. This integral is simply equal to {a}floor(a). Then from floor(a) to floor(b). This is equal to Sum n = floor(a) to n = floor(b) - 1 of f(n)=n. This is tricky to evaluate since floor(a) and floor(b) can be negative or have different signs. Let me simply call this summation I(floor(b) - 1, floor(a)). Then the integral from floor(b) to b simply evaluates to {b}floor(b). So the total integral is {b}floor(b) - {a}floor(a) + I(floor(b) - 1, floor(a)), without loss of generality. As for the summation part, it can be evaluated to T(|floor(b) - 1|) - T(|floor(a)|), where T(n) = n(n + 1)/2. Hence I(floor(b) - 1, floor(a) = [floor(b) - 1]^2/2 + |floor(b) - 1|/2 + floor(a)^2/2 - |floor(a)|/2. Thus the integral from a to b of floor(x) is {b}floor(b) - {a}floor(a) + [floor(b) - 1]^2/2 + |floor(b) - 1|/2 + floor(a)^2/2 - |floor(a)|/2. To integrate some floor[f(x)] instead, repeat the same procedure outlined as for {f(x)}, but rather than replacing {u} by u - floor[f(a)] - n, simply replace it for floor[f(a)] - n, which will be a constant. To integrate ceil(x), notice that ceil(x) = -floor(-x). Then proceed to do a substitution and win. Oh, by the way, the antiderivative of floor(x) = x*floor(x) + c[floor(x)] + C, where c[floor(x)] is some constant for every integer.
@MyOneFiftiethOfADollar
@MyOneFiftiethOfADollar 2 жыл бұрын
That is beautiful. Can't believe you gave up that much brain power for a comment! :) Would consider that as a worthy submission to some Math periodical. You handled the case where limits of integration did not necessarily coincide with the discontinuities(integers) Nice back and forth with ceiling and floor functions. just finished indefinite integral version of this: Summation i=0 to inf ((x-i)^2)/2 which would correspond to a "bunch of" triangles of area 1/2 from a definite integral perspective
@ananyajain4219
@ananyajain4219 3 жыл бұрын
Imagine him as your maths teacher 😍
@rb5727
@rb5727 4 жыл бұрын
Great. Thank u.
@GenerationXSwag
@GenerationXSwag 5 жыл бұрын
Man i love calculus now that you teach me😍
@haradhandatta4824
@haradhandatta4824 5 жыл бұрын
Thanks for evaluating the integral by graphically. Otherwise it may be easily evaluate. {X} is a periodic function with the period =1.So, the integral {X}dx, between 0 to 4=4*integral {X}dx, between 0 to 1=4*integral x dx, between 0 to 1=4*(x^2), between 0 to 1.=4*(1/2)=2. [ integral f(X)dx, from 0 to nT=n*integral f(X)dx, from 0 to T, where T is the period of the function f(X)]
@imanolmanzanares5000
@imanolmanzanares5000 5 жыл бұрын
you are amazing man!!!
@frankenstein69
@frankenstein69 Жыл бұрын
I like your video, understood everything Also I liked your "well well"
@NuptialFailures
@NuptialFailures 5 жыл бұрын
This is similar to the question I asked in your last video: Is the fractional part of 0.999...=0.999... or is it 0? Because 0.999...=1
@yrcmurthy8323
@yrcmurthy8323 5 жыл бұрын
It's equal to 0.9999....
@Theraot
@Theraot 5 жыл бұрын
Do you mean 0.999... (i.e. it continues, but we do not know or do not care for more precision) or do you mean 0.9 recurring (i.e. it continues and we know it repeats 9 foreever)? If the former, then {0.999...} = 0.999... If the latter, then... are you working on the reals (or the complex)? If yes, then {0.999...} = 0 : because 0.999... (recurring) = 1 Otherwise... maybe yes, maybe no.
@yrcmurthy8323
@yrcmurthy8323 5 жыл бұрын
@@Theraot Yep, but I just said it in simpler terms
@angelmendez-rivera351
@angelmendez-rivera351 5 жыл бұрын
0.999... = 1. Therefore, {0.999...} = {1}. {1} = 0, and by the transitive property, {0.999...} = 0. P.S. I am assuming the notation 0.999... represents recurring 9s. Otherwise, the usage of ellipses is actually incorrect, and your question is invalid.
@jakemoll
@jakemoll 5 жыл бұрын
Angel Mendez-Rivera {1} = 0
@12thiit91
@12thiit91 2 жыл бұрын
thanks a lot man
@chrissekely
@chrissekely 5 жыл бұрын
I haven't watched the video yet. If I'm wrong, oh well. Anyway, wouldn't you just integrate the function normally then subtract off the integral of the floor of the function? Not sure how to type calculus. Hope this works for you.. "S" is integral sign (a,b) would indicate integral bounds. So: S(0,4) frac(x) dx = S(0,4) x dx - S(0,4) floor(x) dx
@madhudixitbhajans945
@madhudixitbhajans945 4 жыл бұрын
Sir It is pretty simple by using graphical approach......
@poutineausyropderable7108
@poutineausyropderable7108 5 жыл бұрын
The integral of the floor function is just the sum notation of x shifted by 1. So from ... X(x-1)/2= x^2-x/2 . so the fractional part is x^2/2 -(x^2/2-x/2)=x/2... It just make sens
@danielbenyair300
@danielbenyair300 5 жыл бұрын
Know i saw the previous video so i wander how a function with both would look like
@TrueCheats
@TrueCheats 5 жыл бұрын
Please, how to calculate function erf (x)?
@BigDBrian
@BigDBrian 5 жыл бұрын
I think more generally it would be useful to split the integral, using the definition {x} = x - [x] (just pretend those are the brackets for the floor function) Becuase I think the floor function is easier to handle on its own.
@Akash-vs1yh
@Akash-vs1yh 5 жыл бұрын
Will you please make a video on iit jee Giv and fractional . Function questions
@lucasdepetris5896
@lucasdepetris5896 5 жыл бұрын
Very impressive but can you do the indefinite integral of floor(x) or {x}?
@cerwe8861
@cerwe8861 4 жыл бұрын
So, we can define a number by n={n}+[n] Like we can define it by n=sgn(n)*|n|
@sohinichatterjee5047
@sohinichatterjee5047 4 жыл бұрын
Will you pls help me regarding this problem? f (x) = {x}, 0
@radiotv624
@radiotv624 5 жыл бұрын
How would one handle integrating the fractional part of an arbitrary function of x?
@angelmendez-rivera351
@angelmendez-rivera351 5 жыл бұрын
Radio TV Let u = f(x) so that (f^-1)(u) = x, and dx/du = (f^-1)’(u)*u’, so dx = (f^-1)’(u)*u’ du. Then {f(x)} = {u}, and you can now integrate by evaluate every period of {u} separately. For instance, if your bounds of integration are 0 to 10, then you separate into ten integrals, going from n to n + 1, where n is an integral, and you add them. Then for each interval, replace {u} with u - n, and now integration should be pretty straightforward. If the bounds aren’t integers, then you need an extra case. I will explain more in detail with a comment I will post.
@angelmendez-rivera351
@angelmendez-rivera351 5 жыл бұрын
Easy Mathematics Integration of step functions is all about discrete summation.
@carlosberrio2906
@carlosberrio2906 4 жыл бұрын
Excelente
@aashishukla8900
@aashishukla8900 4 жыл бұрын
thanks for ur help 😍😍😍
@derdiesel2845
@derdiesel2845 5 жыл бұрын
Could you pls make a video solving the equation; „1/x=ln(x)“
@ranitbanerjee956
@ranitbanerjee956 2 жыл бұрын
Sir why you consider the perpendicular of the triangles as 1 as this is not exact 1.
@xdtv2226
@xdtv2226 5 жыл бұрын
Love your video
@danielbenyair300
@danielbenyair300 5 жыл бұрын
2:36 i watched this one first... BUT i did understood that x=[x]+{x} means a number equal to it's digits on the left side of the dot as a whole number (my keyboard don't have the right simbols) and all the fractional part in other words it's just to split the number by the dot
@stephensimpson7794
@stephensimpson7794 5 жыл бұрын
How does this look for the integral. Seems to work for any a and b (|x|/x)(floor(|x|)/2 + (1/2)({|x|})({x}+|floor(x)|-floor(|x|)))
@angelmendez-rivera351
@angelmendez-rivera351 5 жыл бұрын
You could probably rewrite this as [truncate(x) - {x}truncate(x) + sign(x){x}{|x|} + sign(x){x}|floor(x)|]/2
@stephensimpson7794
@stephensimpson7794 5 жыл бұрын
@@angelmendez-rivera351 I was trying to use only mathematical symbols and not programming functions. I just didnt have the key for floor or ceiling on my keyboard
@kavisundram1374
@kavisundram1374 4 жыл бұрын
integration of [x]dx with limits. Where [•] represent greatest integer function. Please please please
@pbj4184
@pbj4184 3 жыл бұрын
It's pretty easy. Try graphing it out
@aryansenvlogs
@aryansenvlogs 5 жыл бұрын
Can you plz do this for me. Find the value of sin16degree.
@user-ic3ty7ts2e
@user-ic3ty7ts2e Ай бұрын
is 0.9 the height for the triangles? cause the domain never goes to 1
@PrashantSingh-tl6zh
@PrashantSingh-tl6zh 2 жыл бұрын
Great👍❤️
@chandraprakashprasad6583
@chandraprakashprasad6583 2 жыл бұрын
Can anyone solve these integration of fractional function part of x^2 from 0 to 2.
@arsalanwani2436
@arsalanwani2436 2 жыл бұрын
Sir ..can solve please integral 0 to 100 fractional part of root x
@tangentofaj
@tangentofaj 5 жыл бұрын
Why isn't this fractional part just a piecewise function? f(x) = {x} where f(x) = x-floor(x) if >= 0; f(x) = x-ceiling(x) if < 0? Wouldn't that be a more accurate result?
@JJ_TheGreat
@JJ_TheGreat 5 жыл бұрын
5:52 But what does the graph look like for negative (-) values of x?
@angelmendez-rivera351
@angelmendez-rivera351 5 жыл бұрын
J.J. The Great The problem is that there are conflicting definitions of the function frac(x) for negative numbers and no agreed upon convention. It is akin to 0^0 in that in different contexts, it is defined differently with no agreed upon arithmetic convention. So the question cannot really be answered without specifying a choice of convention.
@KohuGaly
@KohuGaly 5 жыл бұрын
It depends on the convention. The way BPRP defined it here, the function is periodic and just continues the same way in negatives. That is because he uses floor function, which rounds to nearest smaller integer (ie. integer closer to negative infinity). He may have used different functions, which give the same result in positive numbers, but have different behaviour in negatives. Truncate function rounds towards zero and preserves the sign. So the fractional part would be an odd function.
@senatorlegion5206
@senatorlegion5206 5 жыл бұрын
Do a video about Functional derivative
@loglnlg
@loglnlg 5 жыл бұрын
so, what is integral of fractional part of x^2 from 0 to 4
@angelmendez-rivera351
@angelmendez-rivera351 5 жыл бұрын
кун в очёчках Let u = x^2. Then du/2SqRt(u) = dx. If x = 0, then u = 0, and if x = 4, then u = 16. Hence your Integral is equivalent to integrating from 0 to 16 of {u}/2SqRt(u). Integrating this can be done if we split it into 16 integrals or so. The first Integral goes from 0 to 1 and you integrate u/2SqRt(u) since {u} = u in this interval. This is equal to 1/3. From 1 to 2, you integrate (u - 1)/2SqRt(u), and from 2 to 3 you integrate (u - 2)/2SqRt(u). In general, you integrate (u - n)/2SqRt(u), from n to n + 1, and then you sum from n = 0 to n = 15. If we split the fraction, the first part will be the same for every one of the 16 integrals, so the result for it will be 16/3 for all 16 n. The second term, n/2SqRt(u), integrated from n to n + 1, gives n[SqRt(n + 1) - SqRt(n)] = n*SqRt(n + 1) - n*SqRt(n) = (n + 1)*SqRt(n + 1) - n*SqRt(n) - SqRt(n + 1). We can sum SqRt(n + 1) and the other part separately. The first part of this sum is a telescoping series, so it is simply 16*SqRt(16) - 0*SqRt(0) = 64. As for SqRt(n + 1), we can begin by letting n + 1 be all the perfect squares, so n = 0, n = 3, n = 8, n = 15, and they add to 10. 16 - 10 = 6. We still have SqRt(2) + SqRt(3) + SqRt(5) + ••• + SqRt(15). However, SqRt(2) + SqRt(6) + SqRt(8) + SqRt(10) + SqRt(12) + SqRt(14) = SqRt(2)*[1 + SqRt(3) + 2 + SqRt(5) + SqRt(6) + SqRt(7)] = 3*SqRt(2) + SqRt(2)*SqRt(3) + SqRt(2)*SqRt(5) + SqRt(2)*SqRt(6) + SqRt(2)*SqRt(7). 6 - 3*SqRt(2) = 3*(2 - SqRt(2)), and we can add SqRt(2)*SqRt(3) to SqRt(3) to get SqRt(3)*(1 + SqRt(2)), and then the latter to SqRt(2)*SqRt(6) = 2*SqRt(3) to get SqRt(3)*(3 + SqRt(2)), and this to SqRt(15) to get SqRt(3)*[3 + SqRt(2) + SqRt(5)]. SqRt(2)*SqRt(5) + SqRt(5) = SqRt(5)*[1 + SqRt(2), and SqRt(2)*SqRt(7) + SqRt(7) = SqRt(7)*[1 + SqRt(2)], and this we can add with SqRt(5)*[1 + SqRt(2)] to get [SqRt(5) + SqRt(7)]*[1 + SqRt(2)]. We still have SqRt(11) + SqRt(13) remaining. We can factor 3*SqRt(3) + SqRt(3)*[SqRt(2) + SqRt(5) and have 3*SqRt(3) into 3*[2 - SqRt(2) - SqRt(3). The answer to your Integral is then 5 + 1/3 + 3*[SqRt(3) + SqRt(2) - 1] - SqRt(3)*[SqRt(2) + SqRt(5)] - [SqRt(5) + SqRt(7)]*[1 + SqRt(2)] - SqRt(11) - SqRt(13)
@ss-li4mg
@ss-li4mg 3 жыл бұрын
Hey nice explanation ।love from india 🥰🤩
@arushdixit2792
@arushdixit2792 Жыл бұрын
Thankyou sir 😃😃😃
@yaboylemon9578
@yaboylemon9578 5 жыл бұрын
Definitely a floor function person.
@filmlee5572
@filmlee5572 5 жыл бұрын
I have a good question: integral(sqrt(tanx+ln(sin x))
@luckYowl941
@luckYowl941 5 жыл бұрын
Sir, please what's the integration of (e^y /y )dy
@angelmendez-rivera351
@angelmendez-rivera351 5 жыл бұрын
Kumar Gaurav Cannot be done in terms of elementary functions.
@jakeandrews8393
@jakeandrews8393 5 жыл бұрын
Well well is the new phrase isn’t it isn’t it
@subhasmitasahoo3400
@subhasmitasahoo3400 5 жыл бұрын
Plzzz upload integration over 0 to 1 of [ x ]
@xolmurodtolibjonov2535
@xolmurodtolibjonov2535 4 жыл бұрын
How to integrate [x]^[x]dx
@kimsanov
@kimsanov 3 ай бұрын
But the height is not exact 1 because there is broken continuity. Isn’t it?
@sachintripathi234
@sachintripathi234 3 жыл бұрын
Bro can u help me to solve int of 1 to 4 {x}^[x]dx please
@karthikrambhatla7465
@karthikrambhatla7465 5 жыл бұрын
2.. let me see the answer
@karthikrambhatla7465
@karthikrambhatla7465 5 жыл бұрын
Yay.. got it correct 😊 BlackpenRedPen. But the graph looks cool. area from graph superrr
@michaelhunt2222
@michaelhunt2222 5 жыл бұрын
How do we integrate the sigma function?
@angelmendez-rivera351
@angelmendez-rivera351 5 жыл бұрын
DANK BOI What is the sigma function?
@emanueleusai10
@emanueleusai10 5 жыл бұрын
Nice video
@aaronhalloway7237
@aaronhalloway7237 5 жыл бұрын
Well well!
@jamesartmeier3192
@jamesartmeier3192 5 жыл бұрын
Interesting :) When I think of the fractional part of x, I first think of x modulo 1, as opposed to x minus floor(x). No difference in the positive domain, just for x < 0.
@jimboxb
@jimboxb 5 жыл бұрын
It depends how modulo is defined. In languages such as C, a % b has the same sign as a. We can then define the fractional part as: {x} = ((x % 1) + 1) % 1 If, instead, we defined % to maintain the sign of b, giving us {x} = x % 1.
@Theraot
@Theraot 5 жыл бұрын
That depends on how do you define modulo: en.wikipedia.org/wiki/Modulo_operation Edit: James comment had not appeared for me when I posted mine.
@angelmendez-rivera351
@angelmendez-rivera351 5 жыл бұрын
Also, the fractional part is itself defined differently for negative numbers by different authors. There is no established convention, so talk about negative x with the frac(x) function is nonsense unless you specify a definition.
@prometheusmusic4559
@prometheusmusic4559 5 жыл бұрын
Interesting. Is there ceil function, which rounds number to min bigger integer?
@vincentwilliamrodriguez3572
@vincentwilliamrodriguez3572 5 жыл бұрын
yep
@yrcmurthy8323
@yrcmurthy8323 5 жыл бұрын
The flour function in this video is commonly known as 'Greatest Integer part of x' Represented by [x] The fractional part of x is commonly symbolized as x - [x] represented by {x} The rounding of maximum value is known as 'Least Integer part of x' Represent by (x)
@angelmendez-rivera351
@angelmendez-rivera351 5 жыл бұрын
Yrc Murthy Not at all. There is no established convention for the Greatest Integer function for negative numbers. There are only 4 functions of which we can meaningfully talk about for all x: round up (ceiling function); round down (floor function; round away (there are different names); round toward (truncate function).
@yrcmurthy8323
@yrcmurthy8323 5 жыл бұрын
@@angelmendez-rivera351 You are wrong Mr.
@yrcmurthy8323
@yrcmurthy8323 5 жыл бұрын
@@angelmendez-rivera351 My comment is absolutely correct 100%. What you are saying is wrong. Maybe you're confused. Just ask your teachers or parents or someone who probably knows!
@yrcmurthy8323
@yrcmurthy8323 5 жыл бұрын
Sir, can you make a video on a² + b² = a + ib Please sir. Finding values of a, b
@ytsimontng
@ytsimontng 4 жыл бұрын
Left is real so right must be real, thus b=0. Then a^2=a gives - again - only real solutions a=0 or a=1 (squaring a=i^4 or a=i^-4 actually works, but yeah that's just 1).
@moi2074
@moi2074 5 жыл бұрын
Make a video on (i)! pleasd
@neuneutrinos
@neuneutrinos 5 жыл бұрын
Why not integrate ( pi/2 +atan( tan(pi*x+pi/2) ) )/pi ? ;)
@shokan7178
@shokan7178 5 жыл бұрын
I miss your old intro ;( #YAY
@gamertennyson4010
@gamertennyson4010 Жыл бұрын
We can do it by graph easily
@angelmendez-rivera351
@angelmendez-rivera351 5 жыл бұрын
I prefer the definition frac(x) = x - truncate(x), where truncate(x) := sign(x)*floor(|x|), because for x = -1.7, for instance, truncate(x) = -1, so {x} = -0.7
@KohuGaly
@KohuGaly 5 жыл бұрын
It depends on what behaviour you're after. frac(x) function is commonly used in programming to make periodic functions via lookup table. In that scenario it makes more sense to use floor(x) function, because with truncate(x) you may get negative indexes for the table. On the other hand, the truncate(x) version might make more sense in finance and when x is some sort of symmetric movement. I've personally never came across a scenario, where the truncate version would be the desired behaviour.
@angelmendez-rivera351
@angelmendez-rivera351 5 жыл бұрын
KohuGaly I’m aware it is application dependent. I stand by what I said. Also, the periodic frac function can also be written as f(x) = x mod 1, which many computer languages have.
@KohuGaly
@KohuGaly 5 жыл бұрын
mod functions in computer languages tend to be very vague and inconsistent. Some implement it as x-floor(x), others as x-truncate(x) and yet others as euclidian remainder. But I agree, frac(x) should be the truncate version while mod should be the floor version.
@rafaellisboa8493
@rafaellisboa8493 5 жыл бұрын
good new intro!
@yoyoezzijr
@yoyoezzijr 2 жыл бұрын
in fact ∫{x}dx from 0 to k is k/2 for all k
@priyahasthi1459
@priyahasthi1459 3 жыл бұрын
Which language is this??
@jaredbeaufait5954
@jaredbeaufait5954 5 жыл бұрын
Now do integral from 0 to 2018 of {x}/x
@ThePharphis
@ThePharphis 5 жыл бұрын
before watching: Well I think it would be a periodic line that cuts off at every integer, much like [[x]] - x is. This means the area would be 4 x (l x w / 2) since they are triangular pieces. But length and width are both 1, therefore A = 2 (4 triangles make 2 squares) Ok let's see
@ThePharphis
@ThePharphis 5 жыл бұрын
YES. My familiarity with [[x]] - x has paid off
@MyOneFiftiethOfADollar
@MyOneFiftiethOfADollar 2 жыл бұрын
Yes, periodic with a period of 1. Comes in handy if one is interested in a form for the indefinite integral as well!
@alexanderskladovski
@alexanderskladovski 5 жыл бұрын
Integrate y=x xor k please
@fourier07able
@fourier07able 4 жыл бұрын
0.999... = 1, {0.999...} = 0. A few guys already have answered this question.
@perveilov
@perveilov 5 жыл бұрын
Good, now do ceiling
@perveilov
@perveilov 5 жыл бұрын
@@easymathematik thanks
@89roddy
@89roddy 5 жыл бұрын
One way to write the indefinite integral: ∫{x}dx=(x²+⌊x⌋²+⌊x⌋)/2-x⌊x⌋
@clubstepdj
@clubstepdj 5 жыл бұрын
i'd like to see the anti-derivative... please
@karinano1stan
@karinano1stan 5 жыл бұрын
there is no function that describes it
@angelmendez-rivera351
@angelmendez-rivera351 5 жыл бұрын
Actually, this is incorrect. There is a function which describes the antiderivative of frac(x), and it is not a linear function. If J denotes the antiderivative operator, then J[frac(x)]dx = x^2/2 - J[floor(x)]dx. Floor(x) is a collection of unit step functions summed over their shifts, and their shift parameter contains the set of integers. Each step function is a constant in the continuous intervals, so the antiderivative has slope floor(x), and the continuous segments of the antiderivative are lines. However, each segment has an uncountably infinite number of possible vertical shifts or y-axis intercepts, and for each segment, this vertical shift by a constant is independent from that of the others. Hence, at every continuous interval every integer, we have a new constant of the y-intercept for each segment, which can be denoted as c(floor(x)). This lets J[floor(x)]dx = x*floor(x) + c[floor(x)] + C. Therefore, J[frac(x)]dx = x^2/2 - x*floor(x) + c[floor(x)] + C. Q.E.D.
@ZelForShort
@ZelForShort 5 жыл бұрын
{sqrt2} = 1?
@christoffer9652
@christoffer9652 5 жыл бұрын
No, {sqrt2} = sqrt2 - 1 = about 0.41
@ZelForShort
@ZelForShort 5 жыл бұрын
So whats the room of X? [X] = x? Lol
@siddharth9668
@siddharth9668 2 жыл бұрын
0:07 isn't that doraemon intro song?
@rando_guy
@rando_guy 5 ай бұрын
it is
@i_am_anxious0247
@i_am_anxious0247 5 жыл бұрын
I’m mad that {-|x|} isn’t just -({|x|}) I’m sorry for the absolute values I’m just so paranoid that x could be negative AHH
@dabbghal1604
@dabbghal1604 5 жыл бұрын
your channel deserve millions views but the people prefer songs and something trivial than mathematics and this very sad🙄🙄
@marcuslaurel5758
@marcuslaurel5758 5 жыл бұрын
r/iamverysmart
@dabbghal1604
@dabbghal1604 5 жыл бұрын
@@marcuslaurel5758 😎😚
@priyanshupradhan4388
@priyanshupradhan4388 5 жыл бұрын
Truly an r/iamverysmart
@karthikrambhatla7465
@karthikrambhatla7465 5 жыл бұрын
No problem. We will grow as a community. Let them enjoy their stuff, while we explore and immerse ourselves in math.❤️
@teacul
@teacul 5 жыл бұрын
Wow everyone here is very smart
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