i need help answering this

Question

If we know the values of the sine and cosine of x and y, we can find the value of

cos(x + y)

by using the addition 1Formula for Cosine.

State the formula.

cos(x + y) =

 

Answer 1

The trigonometric expression is .

Rewrite the expression is

Subtraction formula for trigonometric identity: .

Fundamental identities: and .

.