How do you find the antiderivative of int 1/(4-x^2)dx?

1 Answer
Feb 8, 2017

1/4ln|(x+2)/(x-2)|+C.

Explanation:

I=int1/(4-x^2)dx=int1/{(2+x)(2-x)dx

=1/4int4/{(2+x)(2-x)dx

=1/4int{(2+x)+(2-x)}/((2+x)(2-x))dx

=1/4int[cancel((2+x))/{cancel((2+x))(2-x)}+cancel((2-x))/{cancel((2-x))(2+x)}]

=1/4int(-1/(x-2)+1/(x+2))dx

Knowing that, for a!=0, int1/(ax+b)dx=1/aln|ax+b|+c,

I=1/4(-ln|x-2|+ln|x+2|)

=1/4ln|(x+2)/(x-2)|+C.