Question

(sin11π/4 - cos13π/4) * sin(-2.5π) : cos(-25π/3)

Answer 1

$(sinfrac{11pi}{4}-cosfrac{13pi}{4})sin(-2.5pi):cos(-frac{25pi}{3}) = -(sin(3pi-frac{pi}{4})-cos(3pi+frac{pi}{4}))*frac{sin(2pi+frac{pi}{2})}{cos(8pi+frac{pi}{3})} = (-sinfrac{pi}{4}-cosfrac{pi}{4})*frac{sinfrac{pi}{2}}{cosfrac{pi}{3}} = -frac{2sqrt{2}}{2}*frac{1}{frac{1}{2}}=-2sqrt{2}$