### Home > AC > Chapter 12 > Lesson 12.2.1 > Problem 12-40

12-40.

Find the equation of *f*(*x*) graphed below. Homework Help ✎

Identify all of the intercepts.

Write the equation as a factored quadratic since the two values of *x* are known.

*y* = (*x* − 3)(*x* + 1)

Make the equation negative because the parabola opens downward.

*y* = −(*x* − 3)(*x* + 1)

Use a generic rectangle to multiply the factors together. Distribute the negative.