Question

For the function f(x) = x^2 + 3x,a) Find f(-2).b) Is this function linear or quadratic? Justify your answer.c) Will the graph of this function appear as a line or a parabola?

Answer 1

a) Evaluating the function at x= -2 we get:

$f(-2)=(-2)^2+3(-2)=4-6=-2$

b) Notice that the given function has the form:

$y=ax^2+bx+c$

Therefore f(x) is a quadratic function.

c) Since f(x) is a quadratic function its graph is a parabola.