Question

2sin(44)*cos(16) + 2sin²(31)-1

Answer 1

$2sin44cos16+2sin^231-1=2\cdot\frac{1}{2}(sin(44+16)+sin(44-16))+2\cdot\frac{1}{2}(cos(31-31)-cos(31+31))-1=sin60+sin28+cos0-cos62-1=\frac{\sqrt{3}}{2}+cos(90-28)+1-cos62-1=\frac{\sqrt{3}}{2}+cos62-cos62=\frac{\sqrt{3}}{2}$