Question

Mary used the formula sin 50°cos 20º - cos 50° sin 20° to solve a problem. Which of the following identities does this simplify to?

Answer 1

EXPLANATION

Since we have the equation 50°cos 20º - cos 50° sin 20°, we can apply the following relationship:

$\mathrm{Use\:the\:following\:identity}:\quad\sin(A-B)=\sin A\cos B-\cos A\sin B$$Plug\text{ the terms:}$$=\sin(50-20)$$\mathrm{Simplify}$$=\sin30=\frac{1}{2}$

In conclusion, the solution is sin (30) = 1/2