Question

Determine the domain and the range of the function.
f(x) = -4x^2 - 2x - 9

Answer 1

domain is the set of input values (usually x-values) that will give an output (usually y-value)
range is the set of output values from lowest to highest

Answer 2

I know that. I just don't know how to find that...?

Answer 3

consider
what happens when x is negative?
what happens when x is zero?
what happens when x is positive?

a function with the highest degree of 2 is a quadratic
the shape is that of a parabola
general format ax^2 + bx + c when a is negative it opens down