### Home > AC > Chapter 12 > Lesson 12.4.4 > Problem 12-101

12-101.

Find the minimum (the lowest point) of the function *f*(*x*) = 3*x*^{2} + 15*x* − 18. Explain how you know it is the lowest. Homework Help ✎

The vertex is the lowest point of a parabola.

The *x*-coordinate of the vertex is halfway between the *x*-intercepts.

Substitute the *x*-coordinate of the vertex back into the equation to find the *y*-coordinate.

( −2.5, −36.75 )