SOLUTION: Suppose you are given a parabola with 2 points that have the same y-value such as (-3,11) and (6,11). Explain how to find the equation for the axis of symmetry of this parabola, an

Algebra ->  Quadratic-relations-and-conic-sections -> SOLUTION: Suppose you are given a parabola with 2 points that have the same y-value such as (-3,11) and (6,11). Explain how to find the equation for the axis of symmetry of this parabola, an      Log On


   

Question 364576: Suppose you are given a parabola with 2 points that have the same y-value such as (-3,11) and (6,11). Explain how to find the equation for the axis of symmetry of this parabola, and then determine the equation.
Explanation: ___________________
Equation: _______________________
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!


Hi, 

Pt(-3,11) and Pt(6,11) are points on the parabola 

axis of symmetry would be x = 3/2 (half way between -3 and 6, ) 

6 - 9/2 = 3/2 Or -3 + 9/2 = 3/2 

y = ax^2 + bx + c  

3/2 = -b/2a  

b =3 a = -1

y = -x^2 + 3x + c

using ordered pair (-3,11)

11 = -9 - 9 + c

29 = c

y = -x^2 + 3x + 29