MathGloss/Q/Quadratic Function

Examples
$$f(x) = 5x^2 + 8x + 3\,\!$$

$$f(a) = -4a^2 + \tfrac{2}{3}a - 10\,\!$$

$$f(t) = 10t^2 - 15t \,\!$$

$$f(n) = -\sqrt{47}n^2 + 17\,\!$$

$$f(z) = 9z^2\,\!$$