2. (2022春•东城区校级期中)若α\alphaα,β\betaβ都是锐角,且sinα=255\sin \alpha =\frac{2\sqrt{5}}{5}sinα=525,sin(α−β)=1010\sin (\alpha -\beta )=\frac{\sqrt{10}}{10}sin(α−β)=1010,则sinβ=(\sin \beta =(sinβ=( )))