Question

quadratic variation if g(x) varies directly with x2, and g(x) = 50 when x = 5.

Answer 1

If thing1 varies directly with thing2, that means that thing1 = thing2 * a constant

\[g(x) \propto x^2\]implies that \[g(x) = kx^2\]

You know a value of \(g(x)\): \(g(5) = 50\) Plug that into your formula and solve for \(k\).