垃圾中的垃圾

Yes, but exactly what answer is correct will depends on context. The answer given here is 4i, which is a good answer because that is the principle value of the square root function. That said, in any context where you're expected to provide 4 or -4 as the answer to the square root of 16, you should be providing 4i or -4i as the square root of -16, for example if you're asked for the solutions to the equation x^2 = -16. In more advanced mathematics involving complex numbers the square root function is periodic and the best answer may be a formula that describes an infinite family of solutions.

good job

very nice

x²+16=0 x²=-16 x=4i

​@@maganda2009 (4i)² = (-4i)²

Wrong only +7i, - will come from -√-49

If the question was (-16)^0.5 and (-49)^0.5, you would be correct, but when it is written as a square root you only get the positve solutions.

​@@Karan-1888sorry

​@@lukascampidell9376sorry

awesome

Wrong

good going

Sorry, the presenter was wrong and there are perhaps two video. I watched bumbling errors with sqrt(-16) not sqrt(-49).

wow! Have a nice learning!

Absolitely not!🤦🏻‍♂️😂

yeah he missed it

why not?@@Elliotmuji

The minus is gone away with the i

​@@Elliotmuji😂😂 nope - will come from -√-49, Clear your basics first😂

nice one

this is correct