A:No way.
B:Why not?
C:That’s all right.
D:It doesn’t matter.
0.72-0.2=____
0.04×0.7=____
1.25×0.08=____
已知部分锐角三角函数值:sin15°=6-24,sin30°=12,sin45°=22,sin75°=6+24,计算cos75°= ____ .(提示:sin2x+cos2x=1)