Question

Verify each of the following: cos 60 cos 30 + sin 60 sin 30

Answer 1

$\frac{1}{2} \times \frac{ \sqrt{3} }{2} + \frac{ \sqrt{3} }{2} \times \frac{1}{2} \\ \frac{ \sqrt{3} }{4} + \frac{ \sqrt{3} }{4 } \\ 2 \frac{ \sqrt{3} }{4} \\ \frac{ \sqrt{3} }{2}$