SOLUTION: Using the equation {{{ y= a(x-h)^2+k }}} how do you find the values of a and k when h=1, and you have the coordinates (2,7) and (-1,16) At first I tried to find the slope using

Algebra ->  Quadratic Equations and Parabolas -> SOLUTION: Using the equation {{{ y= a(x-h)^2+k }}} how do you find the values of a and k when h=1, and you have the coordinates (2,7) and (-1,16) At first I tried to find the slope using       Log On


   

Question 312635: Using the equation +y=+a%28x-h%29%5E2%2Bk+ how do you find the values of a and k when h=1, and you have the coordinates (2,7) and (-1,16)
At first I tried to find the slope using the coordinates, but I thought that would not work because it's not a line, but I got 10 for a, which was wrong anyway.
Answer by scott8148(6628) About Me  (Show Source):
You can put this solution on YOUR website!
substitute the two points and you have two equations with two unknowns

7 = a(2-1)^2 + k ___ 7 = a + k

16 = a(-1 -1)^2 + k ___ 16 = 4a + k

subtracting equations ___ 9 = 3a ___ 3 = a

substituting ___ 7 = (3) + k ___ 4 = k