2sin ^2(19π/4)+tan^2(8π/3)*tan(-7π/4)

问题描述:

2sin ^2(19π/4)+tan^2(8π/3)*tan(-7π/4)

原式=2sin²(3π/4)+tan²(2π/3)*tan(π/4)
=2(√2/2)²+(-√3)²*1
=4