Chapter 4 Quadratic Functions and Factoring - 4.8 Use the Quadratic Formula and the Discriminant - 4.8 Exercises - Mixed Review - Page 299: 85

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The form of the quadratic function is: $y=a(x-p)(x-q)$ where $a=3\\p=-1\\q=-2$ Thus, the intercepts occur at $(-1,0)$ and $(-2,0)$ The x-coordinate of the vertex is: $x=\frac{p+q}{2}=\frac{-1+(-2)}{2}=\frac{-3}{2}=-1.5$ Find the y-coordinate: $y=3(-1.5+1)(-1.5+2)=3(-0.5)(0.5)=-0.75$ Hence, the vertex is $(-1.5,-0.75)$