首页 > 留学知识库

问题: tga=1/2,sin2a sin^2a=?

解答:

题目不清楚.
sin2a=2sina*cosa=2sina*cosa/1=2sina*cosa/(sin^2a+cos^2a)
=2tana/(tan^2a+1)=4/5
sin2a+sin^2a=4/5+16/25=36/25