Question

Calculus Substitution Integrals (pic)
http://dl.dropbox.com/u/16729527/calc26.jpg
let u = ?, du = ?

Answer 1

put u =x^2

Answer 2

sorrry du=2x dx

Answer 3

doubt?

Answer 4

can you break it down solving it please :D

Answer 5

let u=4-5x^2

Answer 6

\[(1/2)\int\limits_{}^{} dt/(4-5t)\]
this will be the integral after substitution

Answer 7

sorry replace t by u in it as we have u=x^2

Answer 8

would that end up being inverse sin(u)? or leave it alone

Answer 9

no.....not at all

Answer 10

its a linear form

Answer 11

see firstly relax and see all the formulas of integration

Answer 12

http://mathportal.org/formulas/integration_formulas.pdf

Answer 13

see all the forms of integration and then solve questions

Answer 14

ugh still not finding anything unless im suppose to solve sqroot(-1u) then id guess -1/sqroot(u) that doesnt seem right though

Answer 15

\(\large \int \frac{x}{\sqrt{4-5x^2}}dx \)
Let \(\large u=4-5x^2 \)
So \(\large du=-10xdx\rightarrow \frac{-1}{10}du=xdx \)
So \(\large \int \frac{x}{\sqrt{4-5x^2}}dx = \frac{-1}{10}\int \frac{1}{\sqrt{u}} du\)
rewrite that last integral so u can use the power rule...

Answer 16

hmm hahah that makes alot more sense LOL thanks a bunch man these sub integrals confusin me hard but im learning