Question

Find the zeros of each functions by using a graph and a table. F(x)=3x^2–9x–12

Answer 1

We need to find the zeros of the function:

$f(x)=3x^2-9x-12$

To graph the equation we need to find the table. For that we have to find a few values for the equation, we will find the values that go from x=-2 to x= 2.

$\begin{gathered} f(0)=3\cdot0^2-9\cdot0-12=-12 \\ f(1)=3\cdot1^2-9\cdot1-12=-18 \\ f(2)=3\cdot2^2-9\cdot2-12=-18 \\ f(-1)=3\cdot(-1)^2-9\cdot(-1)-12=0 \\ f(-2)=3\cdot(-2)^2-9\cdot(-2)-12=18 \end{gathered}$

We can now use these values to graph the function:

The zeros of the function are the values at which it crosses the x-coordinate, that are

-1 and 4.