Question

Verify the identity.
(1+tan^2u)(1-sin^2u)=1

Answer 1

Try this: substitute (cos 2u)^2 for (1-(sin 2u)^2).

Answer 2

hint:
use identities to help you:
\(1+tan^2(x)=sec^2(x)\)
\(sec(x)=\frac{1}{cos(x)}\)
\(sin^2(x)+cos^2(x)=1\)

Answer 3

these 2 will be useful
- the one mention by mathmale and also tan^2 u = sin^2 u / cos^2 u