如何证明:(1除cos80度)减(根号3除以sin80度)=4
问题描述:
如何证明:(1除cos80度)减(根号3除以sin80度)=4
急求最好今天给我回复
答
1/cos80-根3/sin80
=(sin80-根3cos80)/(sin80*cos80)
=2sin(80-60)/(1/2sin160)
=4sin20/sin160=4