write the expression as a single function of α. cos (0° + α) choose the correct answer below. a. sin α b…

Explanation:

Step1: Use the cosine addition formula

The cosine addition formula is $\cos(A + B)=\cos A\cos B-\sin A\sin B$. Here $A = 0^{\circ}$ and $B=\alpha$. So, $\cos(0^{\circ}+\alpha)=\cos0^{\circ}\cos\alpha-\sin0^{\circ}\sin\alpha$.

Step2: Substitute the values of $\cos0^{\circ}$ and $\sin0^{\circ}$

We know that $\cos0^{\circ}=1$ and $\sin0^{\circ}=0$. Substituting these values, we get $1\times\cos\alpha-0\times\sin\alpha$.

Step3: Simplify the expression

$1\times\cos\alpha-0\times\sin\alpha=\cos\alpha - 0=\cos\alpha$.

Answer:

D. $\cos\alpha$