Question

16 multiple choice 1 point the sine of 72 degrees is 0.95. whats the cosine of 18 degrees? 0.05 1 0.8 0.95

Explanation:

Step1: Recall trigonometric identity

We know that $\sin\alpha=\cos(90^{\circ}-\alpha)$.

Step2: Identify the relationship

Here $\alpha = 72^{\circ}$, and $90^{\circ}-72^{\circ}=18^{\circ}$. So $\sin72^{\circ}=\cos18^{\circ}$.

Answer:

D. 0.95