Int(cosec x)dx Let: u=cos x then: x=arcos u and: dx=-du/sqrt(1-u^2)(adsbygoogle = window.adsbygoogle || []).push({});

Int(cosec x)dx = -Int{1/sqrt(1-u^2)}^2}du = -Int {du/(1-u^2)}

= -(1/2)ln(1-u^2) + C

= -(1/2)ln(sin^[2]x) +C

= ln(cosec x) +C

Yet differentiating back gives -cot x.

Why does this substitution not work?

**Physics Forums - The Fusion of Science and Community**

# Integrating cosec

Have something to add?

- Similar discussions for: Integrating cosec

Loading...

**Physics Forums - The Fusion of Science and Community**