Chapter 5 Polynomials and Polynomial Functions - 5.7 Apply the Fundamental Theorem of Algebra - 5.7 Exercises - Mixed Review - Page 386: 72

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The intercept form of a quadratic function is: $$y=a(x-p)(x-q)$$ where $a=5\\p=-1\\q=-9$ The x-intercepts occur at: $(-1,0);(-9,0)$ The x-coordinate of the vertex is: $x=\frac{p+q}{2}=\frac{-1+(-9)}{2}=\frac{-10}{2}=-5$ Find the y-coordinate: $y=5(-5+1)(-5+9)=5(-4)4=-80$ Hence, the vertex is $(-5,-80)$ The axis of symmetry is $x=-5$