Find the x-intercepts, y-intercept and vertex of the function y = x2 – 5x – 14.

Question

Find the x-intercepts, y-intercept and vertex of the function y = x2 – 5x – 14.

Answer 1

To find the x-intercept, set y=0 and solve for x.  You will have 2 x values.

To find the y-intercept, set x=0 and solve for y.

 

The x-coordinate of the vertex is the average of the x-intercepts.

The y-coordinate of the vertex is the function evaluate at the x-coordinate of the vertex.

 

For example, if the x-coordinate of the vertex is h, then the y-coordinate of the vertex is

 

y = h² - 5h - 14