Question

the equation sec^2x-1=tan^2 x is an identity?

true or false need help

Answer 1

try some values if it doesn't hold then it is not an identity
otherwise it is an identity

Answer 2

thing it is identity

Answer 3

think it is

Answer 4

Start with:\[
\cos^2(2\theta)+\sin^2(2\theta)=1\\
\frac{\cos^2(2\theta)}{\cos^2(2\theta)}+\frac{\sin^2(2\theta)}{\cos^2(2\theta)}=\frac{1}{\cos^2(2\theta)}\\
1+\tan^2(2 \theta)=\sec^2(\theta)\\
\sec^2(2\theta)-1=\tan^2(\theta)
\]

Answer 5

True.