Question

Use the double-angle formulas to rewrite: 12cos squared x-6

Answer 1

\(\bf 12cos^2(x-6)\quad ?\qquad 12cos^2(x)-6\quad ?\)

Answer 2

\[\cos \left( a+b \right)=\cos a \cos b-\sin a \sin b\]
put a=b=x
\[\cos \left( x+x \right)=\cos x \cos x-\sin x \sin x\]
\[\cos 2x=\cos ^{2}x-\sin ^{2}x=\cos ^{2}x-\left( 1-\cos ^{2} x\right)=2\cos ^{2}x-1\]
now you can complete it.