A function written as f(x)/g(x) where both f(x) and g(x) are polynomials is discontinuous only at the points where g(x) = 0. So for the first question, you would solve for the denominator being equal to 0. It is clearly equal to 0 when x = 0, because you can factor out an x^2. To find the other points where it is equal to 0, solve the resulting quadratic equation.