Question

wwhich expression is equivalent to sec^2x-1?

Answer 1

\(\bf \textit{Pythagorean Identities}
\\ \quad \\
sin^2(\theta)+cos^2(\theta)=1
\\ \quad \\
1+cot^2(\theta)=csc^2(\theta)
\\ \quad \\
{\color{brown}{ 1+tan^2(\theta)=sec^2(\theta)}}\)

what do you think?