Question

Use the sun or difference formula for cosine to rewrite cos(x + pi/6) in terms of sine(x) and cos (x). You answer should not have pi/6 in it

Answer 1

cos(x + π/6) = (√3/2)cos(x) - (1/2)sin(x).

Explanation:

To rewrite cos(x + π/6) in terms of sine(x) and cos(x) without explicitly using π/6, we can utilize the sum or difference formula for cosine.

The sum formula for cosine states that cos(A + B) = cos(A)cos(B) - sin(A)sin(B).

In this case, let's consider A = x and B = π/6. Using the sum formula, we have:

cos(x + π/6) = cos(x)cos(π/6) - sin(x)sin(π/6).

Now, we can simplify further. The value of cos(π/6) and sin(π/6) can be determined using the unit circle or trigonometric identities.

cos(π/6) = √3/2 and sin(π/6) = 1/2.

Substituting these values into the equation, we get:

cos(x + π/6) = cos(x)(√3/2) - sin(x)(1/2).

Thus, cos(x + π/6) can be expressed in terms of sine(x) and cos(x) as:

cos(x + π/6) = (√3/2)cos(x) - (1/2)sin(x).