The graph of a certain quadratic y = ax^2 + bx + c is a parabola with vertex (-4,0) which passes through the point (1,75) What is the value of a?
Vertex (-4,0)
Vertex form y = a ( x+4)^2 + 0
sub in the point (1,75) to calculate 'a'
75 = a ( 1 +4)^2 so a = 3