OK, here's the question: Differentiate x.ln(4-(x^2)) Which is: ln(4-(x^2)) - (2(x^2))/(4-(x^2)) Now, find an antiderivative of (x^2)/(4-(x^2)). Answer says -x + ln( (2+x)/(2-x) ) +c How do I get that? The comments say "Many failed to recognise the need to divide" - What does that mean? I'm so damn stuck! Please help! Any is appreciated.