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Calculus BC- antideriv of functions with multiplicative terms

 
 
zselina的头像
Calculus BC- antideriv of functions with multiplicative terms
zselina - 2022年08月7日 Sunday 11:45
 

Hello, 

I am confused on getting antiderivatives of functions with multiplicative terms (ex. denominators).

Specifically, #11 of 7/18 hw, get the antiderivative of x/(x^2 + 1)? To me this seems like a triple nested function like (f(g(h(x)))). I also cannot apply the trick of NUM/(denom1 * denom2) =  A/denom1 + B/denom2 as (x^2 + 1) is non-factorable over the reals. I also can't readily use FOIL to break this derivative function into additive discrete terms because of the denominator.

I am also a bit lost on Euler's method of stepping; I got a different answer than the key

Below please find the problem

Thank you!

 
WangDr. Kevin的头像
Re: Calculus BC- antideriv of functions with multiplicative terms
WangDr. Kevin - 2022年08月7日 Sunday 15:09
 

For this type of questions you can try substitution method: Let $u=x^2+1$, and then $du=2xdx$, and go from there.