How do I find the antiderivative of f(x) = (5x)/(10(x^2-1))?

1 Answer
Jan 29, 2015

I would first manipulate the argument to get it in a form which is easier to integrate:
Simplifying the 5 and 10 and transforming x^2-1 in a product you get:

int(5x)/(10(x^2-1))dx=int(x)/(2(x-1)(x+1))dx=

I then rearrange to get a sum introducing an additional 1/2;

=int1/4*(1/(x-1)+1/(x+1))dx=

(which is equivalente to the starting one: int(x)/(2(x-1)(x+1))dx)

And finally:

=int1/4*(1/(x-1)+1/(x+1))dx=1/4[ln(x-1)+ln(x+1)]+c
or
=1/4[ln(x^2-1)]+c