Answer:
-cos(2A)
Step-by-step explanation:
We know that (a+b) (a-b) = a^2-b^2
So it means we can simplify to sin^2(A)-cos^2(A) and we know cos^2(A) - sin^2(A) = cos(2A) but we will just multiply by -1 and we get - cos(2A)
