10sin^2x + 3 + 5sin^2x(pi/2 - x)
= 10sin^2x + 3 + 5(sin^2x pi/2 - sin^2x x)
= 10sin^2x + 3 + 5(pi/2 sin^2x - x sin^2x)
= 10sin^2x + 3 + 5pi/2 sin^2x - 5x sin^2x
= 10sin^2x + 3 + 5pi/2 sin^2x - 5x sin^2x
= (10 + 5pi/2)sin^2x - 5x * sin^2x + 3