SOLUTION: Find a quadratic model for the set of values: (-2, -20), (0, -4), (4, -20)

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: Find a quadratic model for the set of values: (-2, -20), (0, -4), (4, -20)      Log On


   

Question 1032297: Find a quadratic model for the set of values: (-2, -20), (0, -4), (4, -20)
Found 2 solutions by josgarithmetic, solver91311:
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
You should be able to take advantage of the given root and the easily found symmetry axis with the use of the standard form equation.

Two x values give the same y value of -20. This tells you where the symmetry axis is.

y=a%28x-1%29%5E2%2Bk----a starter equation

Point (-2,-20) gives a%2A%28%28-2%29-1%29%5E2%2Bk=-20
and
point (4,-20) gives a%28%284%29-1%29%5E2%2Bk=-20
and the system easily solvable.

Answer by solver91311(24713) About Me  (Show Source):
You can put this solution on YOUR website!

A quadratic function has the form:



If then



Likewise, for and



and




Which yields the 3X3 system:





Which can be simplified to the 2X2 system:




Solve the 2X2 system for and . You already know that


John

My calculator said it, I believe it, that settles it