已知sinβ=1/5,sin(a+β)=1,求sin(2a+β)=实在不会做--

Question

已知sinβ=1/5,sin(a+β)=1,求sin(2a+β)= 实在不会做- -

Answer 1

sin(a+β)=1
a+β=2kπ+π/2
∴ sin(2a+β)
=sin[2(a+β)-β]
=sin(4kπ+π-β)
=sinβ
=1/5