已知sina=2根号5//5,π/2
问题描述:
已知sina=2根号5//5,π/2
答
sina=2√5/5
sin^2a=4/5
cos^2a=1/5
因为π/2
已知sina=2根号5//5,π/2
sina=2√5/5
sin^2a=4/5
cos^2a=1/5
因为π/2