Online Course Discussion Forum

Math Challenge I-C #4.24

Picture of Kerry Zhang
Math Challenge I-C #4.24
by Kerry Zhang - Monday, October 8, 2018, 10:08 AM

I don't I understand how to do this problem.

Picture of David Reynoso
Re: Math Challenge I-C #4.24
by David Reynoso - Tuesday, October 9, 2018, 11:22 AM
A parabola has a line of symmetry, which goes through the vertex. In this case the line of symmetry is the vertical line $x=8$, which means the vertex has $x$-coordinate $8$ and points equidistant to the line have the same $y$ coordinate. For example if the point $(4,10)$ is on the parabola, the point $(12,10)$ is also on the parabola, since $8 - 4 = 4$ and $8 + 4 = 12$.