The cross-section of a drain is to be an isosceles trapezium, with three sides of length 2 metres, as shown. Find the angle θ that maximises the cross-sectional area, and find this maximum area.
@noone769215 күн бұрын
Hello, I have a simple and dumb question to ask. Why are we changing the integral f(x)dx from limit [a,x] to a dummy variable f(t)dt. To put it clear why are we using the dummy variable t u or v specifically ?. What will the consequences if we still integrste without changing it to the dummy variable?
@slcmathpc14 күн бұрын
It is to avoid what is commonly known as a "clash of variables". The actual variable in this instance is the upper bound of integration, which we chose to label as "x". The variable, say "v", in the integrand "f(v)dv" is what is known as a "dummy variable", since it is not a consequential variable and is completely independent of the upper bound of integration "x". Writing the integrand "f(v)dv" as "f(x)dx" seems to suggest that the "x" in "f(x)dx" has something to do with the upper bound of integration "x", which is simply not the case. Writing the integrand as "f(x)dx" and using "x" as the upper bound of integration causes a "clash" between the two expressions, which again, have nothing to do with one another. Hope this clears things up!
@noone769214 күн бұрын
@@slcmathpc thank you
@stevenkaban15 күн бұрын
thank you very much for proving a lot of infinite series' tests to the world
@FaizMuhammadsahto18 күн бұрын
Excellent sir ❤
@user-ey3oy4rw8o18 күн бұрын
Neat and dainty hand writing. 👍It would be great if you can explain it.
@yuutek416523 күн бұрын
How did you get that with any x, f(x)=(x-a)q(x)+f(a) if f(a)=C only when x=a?
@slcmathpc18 күн бұрын
Since C is a constant, then it must be the same for any value of x chosen.
@Historyvlogsbyfaiz12324 күн бұрын
Thanks ❤
@mvas1lАй бұрын
45:27 shouldnt the last element of v3 be 1 since you didnt scale it?
@shekharjoshi7292Ай бұрын
Such a clear derivation. Realy amazing.
@RanBlakePianoАй бұрын
I can t hear you
@salmonroe5608Ай бұрын
thank you dear sir for this demonstration. It helped me review my studies. Have a great day.
@Victual88Ай бұрын
Thanks Man for the great proof! minor correction at 1:20 (you wrote + said (AB) is a P x M matrix. I think you meant (AB)^T is a P x M matrix. (It's still definitely clear what you mean btw)
@LorettaAhenkan-bi9hbАй бұрын
you said cube root of negative is negative so why did you write x not -x
@slcmathpcАй бұрын
Because x is negative. ;-)
@AlfredKatema-fg1qeАй бұрын
Where did you get those figures 7,10,15 and 22 because when I square matrix a Am getting those figures
@ObiajuluEmma-Ebere2 ай бұрын
Excellent!! From Nigeria, thank you.
@Vedant-xf9qn2 ай бұрын
bro does not get enough credit
@Johnsonmoses-hp1kz2 ай бұрын
Me the question is not stated befor sloving how i meant going to understand
@Sarah._.s8892 ай бұрын
Very clear and well explained Thank you very much🙏
@chrisprice85472 ай бұрын
Amazing. Helped me with my Uni assignment. Much love.
@DeepanM-xm6fn2 ай бұрын
Well explanation
@ronimandiviiia25142 ай бұрын
Ya bro, it was really nice to understand this basic problem. Thank you so much to describe this in easy and brief manner. Just keep it up.😊
@tarekbouchlaghem72772 ай бұрын
Thanks for the simplification
@eiconmatheus68122 ай бұрын
I am starting to hate school especially when math is included
@teslayt9402 ай бұрын
Explained a 3hr lecture in less than 1hr
@sumsumiho2 ай бұрын
Thank you so much for such a detailed and easy-to-follow explanation!
@Emma-ki3fv3 ай бұрын
This is the first time I understood this thank you, it’s been 2 months since my professor taught it.
@HannahDavies-dp6qn3 ай бұрын
in final step, is the tangent line slope calculation mean to say f(x)dx /g(x) dx evaluated at c (not the derivatives) thank you
@slcmathpc3 ай бұрын
It is indeed f'(x)dx/g'(x)dx evaluated at x=c.
@kungfooman3 ай бұрын
What if you have x and x squared in the equations? If you define x squared to be... lets say... "a", then the non-squared x turns into a square root and it's still non-linear?
@slcmathpc3 ай бұрын
Not every non-linear system can be effectively turned into a linear one; it only works for "slightly non-linear" systems. Of course, in your example, you could let a=x and b=x^2, and if the system can then become linear, you can solve it, but at the end, you would have to check that the values of a and b obtained are consistent with the fact that b=a^2.
@kungfooman3 ай бұрын
@@slcmathpc Thank you for the feedback, my example system is: (1) x²+y²=125 and (2) x+y=15... we can already see that it's {x=10,y=5} and vice versa. But I fail to find a nice way to turn it into a linear system, even tho the answer already seems so obvious/simple. My best hope was: let a=a+y, b=xy and take the binomial form of (1) which is (3) (x+y)²-2xy. Then we will have as a result: a²-2b=125 and a=15 and if you solve that you get {a=15, b=50} which is correct since a=x+y=10+5=15 and b=x*y=10*5=50. Still not linearly solvable... maybe it's an example of a non-slightly non-linear system? Lol
@Festus20223 ай бұрын
Great explanation. Thanks
@user-wp3fu7eu1d3 ай бұрын
Real Goat
@YonatanHaile-rf2jm3 ай бұрын
this video was gonna make me question the things i know about this topic, I don't recommend this video
@JnSubli3 ай бұрын
Hi, My understanding for series to diverge is when "nth divergence test" must also meet this criteria lim n→∞ aₙ = lim n→∞+1 aₙ ......= lim n→∞+∞ aₙ ≠ 0 else they would either Diverge (don't summed up to a real number) or Undefined (if all summed up to zero and infinitely repeating). Example for aₙ terms that are lim n→∞ (-1)^n or lim n→∞ sin(n) is Undefined. And for your case above lim n→∞ |aₙ| = ∞ ⇒ lim n→∞ aₙ ≠ 0 it may not meet lim n→∞ aₙ = lim n→∞+1 aₙ because lim n→∞ aₙ and n→∞+1 aₙ could also be +- aside from ++ or -- according to the ratio test |aₙ₊₁/aₙ| > 1. It Diverge only because the terms didn't summed up to zero. What do you think sir?
@fidget54373 ай бұрын
Ten/ten video, helps out a ton! Props for putting in the work to make this video's explanation perfectly comprehensible.
@user-mn2mc3pd4d3 ай бұрын
thanks
@hulusiserdaryldrm88543 ай бұрын
i was like WTF ?!? when i saw she is a male then i realized that he said we should correct it with "person" lol
@hulusiserdaryldrm88543 ай бұрын
but after a 10 years , thanks a lot ! you made me understand this topic which other 5 videos failed to do :D
@Tukskun3 ай бұрын
thank you boss
@ahmadfakhir74103 ай бұрын
Thanks very good example👍💖💚
@IlayShriki3 ай бұрын
A great video!
@Someone_Named_GlowingSubspace3 ай бұрын
Did somebody call my name?
@jamesboumalhab73373 ай бұрын
Appreciate you g
@user-sm7ru4vu2b4 ай бұрын
Great vid
@helbertrodriguez64494 ай бұрын
absolute legend
@lunaticnomad04 ай бұрын
Nice content, was a great refresher for me!
@MOHINIVERMA-cp5ey4 ай бұрын
best vedio on this topic
@jenm14 ай бұрын
flawless vid
@abhinaba91904 ай бұрын
I found your derivation to be very helpful.....but I have just one question..... The graph a displacemnt-time graph right?
@slcmathpc4 ай бұрын
Yes, you should think of f(t) as the position of an object moving in a linear fashion as a function of time. :-)
@abhinaba91904 ай бұрын
So that means the position of the object is in a continuous function of time.....like for example for a free falling body changing its postion or accelerating uniformly in the influence of gravity.....with change in time.....
@slcmathpc4 ай бұрын
Yep, those are valid examples!
@abhinaba91904 ай бұрын
Thank u:-)
@user-kp2uk3cg4g4 ай бұрын
Thank you prof for the wonderful explanation. I study in Stanford; according to people our faculties are world class. However, I could not understand 1/10th of what I understood here.
@surendrakverma5554 ай бұрын
Very good. Thanks
@errorhostnotfound11654 ай бұрын
I know that he said that finding the generic formula for i^k is supposed to be an exercise, but I have gotten stuck at (n+1)sum((2i-1)^(k/2)) - sum(i(2i-1)^(k/2)), so what is it? I haven't been able to find anything online so far
@slcmathpc4 ай бұрын
The idea that I have presented in these videos only allows one to find the summation formula for i^k recursively, so you can find that of i^3, then i^4, then i^5, and so on, but you cannot jump to say i^20, without first finding the formula for all of the powers lower than 20. Hope this clarifies things. :-)
@lesserafimseason4 ай бұрын
God I swear this helped me understand the concept better thanks so much.