Question

What is the completion to sin^2theta+tan^2theta+cos^2theta?

Answer 1

it's all about knowing your identities!
\[\sin^2(\theta)+\cos^2(\theta)=1\]
is one identity
use that and you're left with \[1+\tan^2(\theta)= ?\]

Answer 2

oh look, another trig identity! \[\tan^2(\theta)+1=\sec^2(\theta)\] and then you're done

Answer 3

Ohh ok. Thank you!