Question

Integrate 1/((x-1)(x+2))

Answer 1

= A / (x-1) + B / (x+2)
1 = A(x+2) + B(x-1)

let x = 1, A = 1/3
let x = -2, B = -1/3

integrate 1/3 / (x-1) - 1/3 (x+2)
= 1/3 * (ln|x-1|) - 1/3 * (ln|x+2|) + c
= ( ln |(x-1)/(x+2)| ) / 3

Answer 2

amirite?

Answer 3

Yes , thank you