sin(3π/2-x/2)√[(1+tanx/2)²+(1-tanx/2)²]=-cos(x/2)√[1+2tan(x/2)+tan²(x/2)+1-2tan(x/2)+tan²(x/2)]=-cos(x/2)√[2+2tan²(x/2)]=-cos(x/2)√[2+2sin²(x/2)/cos²(x/2)]=-cos...