tan(π-α)=2 =>tanα=-22sin(3π+α)cos(5/2π+α)+sin(3/2π-α)sin(π-α)=(-2sinα)(-sina)+(-cosa)sina=2sin² α-cosasina=2tan²acos²a-cos²atana=cos²a[2x4+2]=10cos²a=10/sec&...