证明 2(sin2a+1)/1+sin2a+cos2a=tana+1 2(sin2a+1)/1+sin2a+cos2a=tana+1
问题描述:
证明 2(sin2a+1)/1+sin2a+cos2a=tana+1
2(sin2a+1)/1+sin2a+cos2a=tana+1
答
2(sin2a+1)/1??????
答
2(sin2a+1)/1+sin2a+cos2a
=2(sina+cosa)2/[2cosa(sina+cosa)]
=(sina+cosa)/cosa
=tana+1