求三角比各值的解

1. θ=75-(90-43)=28
2.tan (x+15)= 1/tan(x+60)
sin(x+15)sin(x+60)=cos(x+15)cos(x+60)
0=cos(x+15)cos(x+60)-sin(x+15)sin(x+60)
cos90=cos(x+15+x+60)
cos90=cos(2x+75)
90=2x+75
x=7.5???
3. [(cos(90-θ)^2)]/(1-cosθ) -sin(90-θ)
= (sin(θ)^2- cosθ + (cosθ)^2)/(1-cosθ)
=1
4.
=(sinθ )^2/ ((sinθ) ^2/(cos θ)^2) * (2/ [(cosθ)^3* (sinθ)^2/(cosθ)^2])
=(cos θ)^2 * 2 (sinθ)^2
=2(cotθ)^2
5.=sin^2(36)+cos^2(36)=1
6.=cos75*sin75/cos75-sin75
=sin75 - sin75=0