已知tan=6,2sinacosa+sin^2的值

问题描述:

已知tan=6,2sinacosa+sin^2的值

sina^2=36cosa^2
sina^2+cosa^2=1→cos^2=1/37
式子同除cosa^2再乘cosa^2得
(2tana+tana^2)cosa^2=(12+36)1/37=48/37答案48/37