write the expression as a function of θ, with no angle measure involved. cos (60° - θ) cos (60° - θ) = □…

Explanation:

Step1: Use the cosine subtraction formula

The formula for (\cos(A - B)=\cos A\cos B+\sin A\sin B). Here (A = 60^{\circ}) and (B=\theta). So (\cos(60^{\circ}-\theta)=\cos60^{\circ}\cos\theta+\sin60^{\circ}\sin\theta).

Step2: Substitute the values of (\cos60^{\circ}) and (\sin60^{\circ})

We know that (\cos60^{\circ}=\frac{1}{2}) and (\sin60^{\circ}=\frac{\sqrt{3}}{2}). Substituting these values, we get (\cos(60^{\circ}-\theta)=\frac{1}{2}\cos\theta+\frac{\sqrt{3}}{2}\sin\theta).

Answer:

(\frac{1}{2}\cos\theta+\frac{\sqrt{3}}{2}\sin\theta)