因为α为锐角,β为钝角所以,π/2≤α+β≤3π/2sin(α+β)=33/65所以,cos(α+β)=-56/65而π/2≤β≤π所以,cosβ= -5/13sinβ=12/13所以,sinα=sin((a+β)-β)=sin(a+β)cosβ-cos(a+β)sinβ=33/65 * (-5/13) - (-...