determine-the-exact-value-of-the-following-expression-by-writing-it-as-the-cosin

Question

Determine the exact value of the following expression by writing it as the cosine of a double angle.

cos² 112.5° - sin² 112.5°

Accepted Answer

-(√2)/2

Answer

(√2)/2

Answer

-1/2

Answer

-(√3)/2

Determine the exact value of the following expression by writing it as the cosine of a double angle.cos² 112.5° - sin² 112.5°