The graph of a certain quadratic y = ax^2 + bx + c is a parabola with vertex (4,0) which passes through the point (5,7). What is the value of a?
Vertex form
y = a ( x - h)^2 + k where (h,k) is the vertex and (x,y) a point on the graph....so....
7 = a ( 5 -4)^2 + 0
7 = a * 1^2
7 = 1a
a = 7
