SECTION 6.2

Question 1

What is the double angle formula for cosine?

Answer 1

1. cos(2x) = cos²x - sin²x
2. cos(2x) = 2cos²x - 1
3. cos(2x) = 1 - 2sin²x

Question 2

How do you determine the domain of half-angle equations?

Answer 2

Divide the given inequality by 2.