Step 4 is wrong. the answer is 1/8, she changed sign on 2^(-3) to 2^(3) without moving it to numerator
i will solve it first i need full form
The answer is
<span>D. y = 4cos(-x) - 2
proof
cosine is an even function, it means cos(-x) = cosx
so </span>y = 4cos(-x) - 2 = y = 4cos(x) - 2
