181k views
5 votes
What are the zeros of f?f (x) = x² + 8x + 12A) 2 and 6B) 3 and 4 C) -3 and -4D) -2 and -6

User DelegateX
by
4.0k points

1 Answer

6 votes

To find the zeros of f(x), follow the steps below.

Step 01: Use the quadratic formula.

For a quadratic equation y = ax² + bx + c, the zeros are:


\begin{gathered} x=\frac{-b\pm\sqrt[]{b^2-4ac}}{2a} \\ \end{gathered}

Step 02: Substitute the coefficients of f(x) in the quadratic formula.

For f(x) = x² + 8x + 12, the formula is:


x=\frac{-8\pm\sqrt[]{8^2-4\cdot1\cdot12}}{2\cdot1}

Step 03: Solve the quadratic formula.


\begin{gathered} x=\frac{-8\pm\sqrt[]{64^{}-48}}{2} \\ x=\frac{-8\pm\sqrt[]{16}}{2} \\ x=(-8\pm4)/(2) \end{gathered}

And finally, find the zeros:


\begin{gathered} x_1=(-8-4)/(2)=-(12)/(2)=-6 \\ x_2=(-8+4)/(2)=-(4)/(2)=-2 \end{gathered}

Answer: D) The zeros are -2 and -6.

User Sbrattla
by
3.5k points