Question

(9-cos^2(t))

Answer 1

What do you have to do with this ? expand, proof or verify (and you just forgot the "=" ) , or what ?

Please \(\large\color{red}{ \bf d }\)\(\large\color{blue}{ \bf o }\)\(\large\color{red}{ \bf n }\)\(\large\color{blue}{ \bf ' }\)\(\large\color{red}{ \bf t }\) hesitate to reply

Answer 2

Actually, simplify: (3 - cos(x)) times (3 + cos(x))

Answer 3

using Pythagorean identities