Question

Take the integral of sqrt(64-x^2) dx.

Answer 1

u=64-x^2?

Answer 2

Yes

Answer 3

Oh, no, this is not a u-sub problem. Didn't look at your problem that well.

Answer 4

I just knew it, then what's the strategy?

Answer 5

Bleh, trig sub. Which I'm not fond of, or good at. u = sqrt(64)sin(x), du/dx = sqrt(64)cos(x). Not too good at the next part...

Answer 6

Replace x with sqrt(64)sin(x) I mean. The terms underneath the square root total 64cos^2(x)

Answer 7

Man, I'm losing it. It's something around those lines. Sorry for getting your hopes up lol.

Answer 8

use trigonometric substitution first take factor from the sqrt

Answer 9

\[\int\limits_{}^{}\sqrt{64-x^2}dx\]
\[8\int\limits_{}^{}\sqrt{1-\frac{ x ^{2} }{ 64 }} dx\]

Answer 10

Thank you.

Answer 11

\[8\int\limits_{}^{}\sqrt{1-(\frac{ x }{ 8 })^{2}} dx\]

Answer 12

np but can u complete it ?

Answer 13

@Idealist