Question

Q is proportional to p squared and q is inversely proportional to r cubed using k as the final constant of proportionality write an equation for p in terms of r

Answer 1

let sin(x)=u , let cos(x)=v du/dx = cos(x),   dv/dx = -sin(x) d[sin(x)cos(x)]/dx = v.du/dx + u.dv/dx = cos^2(x) - sin^2(x)

Answer 2

The answer should be
P^2 = k * r^3