The graph of a certain quadratic y = ax^2 + bx + c is a parabola with vertex (-4,0) which passes through the point (7,1). What is the value of a?
ax^2 + bx + c
Since the vertex is (-4,0) we have a double root at x = -4
So....the equation becomes
y = a ( x + 4)^2....and (7,1) is on this graph....so....
1 = a ( 7 + 4)^2
1 = a * 11^2
1 = 121 a
a = 1/ 121
