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) = the vertex and (x,y) is another point on the graph
7 = a ( 5 - 4)^2 + 0
7 = a(1)^2
7 = a
