sin15.30.45.60.75.90.105.120.135.150.165.180 cos15…90… ten15.30…各等于几分之几.

sin0° = sin180°= 0
sin15°= sin165°= (√6-√2)/4
sin18°= sin162°= (√5-1)/4
sin30°= sin150°= 1/2
sin45°= sin135°= √2/2
sin60°= sin120°=√3/2
sin75°= sin105°= (√6+√2)/4
sin90°= 1