The maximum volume of a right circular cylinder if the sum of its radius and height is 6 m is

The equation of the normal to the curve $2 x^2+y^2=12$ at the point $(2,2)$ is

The area of the square increases at the rate of $0.5 \mathrm{~cm}^2 / \mathrm{sec}$. The rate at which its perimeter is increasing when the side of the square is 10 cm long, is

The equation of normal to the curve $$y=\sin \left(\frac{\pi x}{4}\right)$$ at the point $$(2,5)$$ is