SOLUTION: The vertex of this parabola is at (2, -4). When the x-value is 3, the y-value is -1. What is the coefficient of the squared expression in the parabola's equation? A) 3 B) 5

Algebra ->  Quadratic-relations-and-conic-sections -> SOLUTION: The vertex of this parabola is at (2, -4). When the x-value is 3, the y-value is -1. What is the coefficient of the squared expression in the parabola's equation? A) 3 B) 5       Log On


   

Question 950873: The vertex of this parabola is at (2, -4). When the x-value is 3, the
y-value is -1. What is the coefficient of the squared expression in the parabola's equation?
A) 3
B) 5
C) 1
D) -2
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
The last part of the description simply means the parabola has a point (3,-1).

y=a%28x-h%29%5E2%2Bk
y=a%28x-2%29%5E2-4, using given vertex
a%28x-2%29%5E2=y%2B4
a=%28y%2B4%29%2F%28x-2%29%5E2
a=%28-1%2B4%29%2F%283-2%29%5E2 , using the other given point
-
a=3%2F1%5E2
highlight%28a=3%29------------the answer to the actual question part.