化简(sina)^2*tana +(cosa)^2*cota+2sinacos

问题描述:

化简(sina)^2*tana +(cosa)^2*cota+2sinacos

sin²atana+cos²acota+2sinacosa
=sin³a/cosa+cos³a/sina+2sinacosa
=(sin²a+cos²a)²/(sinacosa)
=2/sin2a
=2csc2a