Question

2sin45cos15 ? evaluate

Answer 1

`sqrt3/2+1/2=1/2(sqrt3+1)`.

Explanation:

Recall that, `2sinxcosy=sin(x+y)+sin(x-y)`.

`x=45, and, y=15 rArr x+y=60, and, x-y=30`.

`:. 2sin45cos15=sin60+sin30=sqrt3/2+1/2=1/2(sqrt3+1)`.