Question

数学三角函数化简题2(sin 120)^2+(sin 30)^2

Answer 1

2(sin 120)^2+(sin 30)^2

=2(sin 60)^2+(sin 30)^2

=2(cos30)^2+(sin 30)^2

=2cos²30+sin²30

=cos²30+cos²30+sin²30

=cos²30+1

=（√3/2）²+1

=3/4+1=7/4