Question

A parabola has a vertex at (-2,6) and roots at 7 and m. Find the value of m

Answer 1

So m= - 11

Explanation:

* THe vertex is (-2,6), then the equation is y = a(x+2)^2 +6, a is to find out.

* A root is 7 means x=7 and y=0, then :

0 = a(7+2)^2 +6

0=81a+6 or a= -6/81 = -2/27.

* We have the equation: y= -2/27 (x+2)^2 +6=-2/27 [ (x+2)^2-81]

y= -2/27 (x-7)( x+11).

So m= - 11

Hope that you understand.