Question

can you use trigonometric substitution in this?

Answer 1

What is this?

Answer 2

sorry, I mean this

Answer 3

integral sign dx/(9-x^2)

Answer 4

I tried trigonometric substitution
a^2 - u^2 : Let u = a sin (theta)

but, I get different result when I use partial fractions

Answer 5

@UnkleRhaukus

Answer 6

additional question:
based from my book, it is used with radicals in the form of

Answer 7

Sqrt(a^2 - u^2)
Sqrt(a^2 + u^2)
Sqrt(u^2 - a^2)

but why is it my teacher said that I should use trig substitution in this:

dx/(x^2 +1)^2

Answer 8

this looks like a tricky integral , i cannot remember how to do this,
do you have some working?

Answer 9

which one?

Answer 10

@TuringTest

Answer 11

you want to solve
integral dx/(x^2 +1)^2
with a trig sub?

Answer 12

i think we were trying to do

∫dx/(9-x^2) first,

Answer 13

just factor out the 9 first

Answer 14

(1/9)∫dx/(1-(x/3)^2)
sin(t)=x/3
...

Answer 15

dx=3cos(t)dt

do I need to continue?