Question
Integrate ç (x^3)/ã((x^2)+4) dx
Answers
Steve
I think you want √(x^2+4) but I don't know what the ç indicates.
copy/paste mangles various fonts
copy/paste mangles various fonts
Athlete 34
Here is what I meant to put:
Integrate ç(x^3)/ã((x^2)+4) dx
Integrate ç(x^3)/ã((x^2)+4) dx
Athlete 34
it keeps messing up...but you have the square root right and the ç was supposed to be the S shaped symbol.
Steve
so, you want
∫ x^3/√(x^2+4) dx
let u^2 = x^2+4
2u du = 2x dx
x^2 = u^2 - 4
∫ x^2/√(x^2+4) x dx
= ∫(u^2-4)/u u du
= ∫ u^2-4 du
= 1/3 u^3 - 4u
= 1/3 u (u^2 - 12)
= 1/3 √(x^2+4) (x^2 - 8)
∫ x^3/√(x^2+4) dx
let u^2 = x^2+4
2u du = 2x dx
x^2 = u^2 - 4
∫ x^2/√(x^2+4) x dx
= ∫(u^2-4)/u u du
= ∫ u^2-4 du
= 1/3 u^3 - 4u
= 1/3 u (u^2 - 12)
= 1/3 √(x^2+4) (x^2 - 8)