- #1

- 5

- 0

y= (e^x)/(1+(e^x)^2)

So I set u=e^x

du=e^x

then I am stuck.

the second question is (btw [{( are all used as parentheses to make it abit less confusing)

y=(x^2)/[{(x^3)+1)}^12]

I setted u=(x^3)+1

du=3x^2

(1/3)du = (x^2)dx

(1/3)integral sign [1/(u^12)]du

stuck there after

and 3

y=[(lnx)^3]/x

do i set x as u? or lnx?

Last of all I have no clue on number 4 which is

y=sin(2x)*e^[cos(2x)]

Many thanks!