已知tan=6,2sinacosa+sin^2的值
问题描述:
已知tan=6,2sinacosa+sin^2的值
答
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