The graph of a certain quadratic y=ax2+bx+c is a parabola with vertex (-4, 0) which passes through the point (1, -75). What is the value of a?
hint
The roots will be at x=−b±√b2−4ac2a
the axis of symentry will be the half way point between these roots.
What will that be, as fa as the formula is concerned ?
Sketch it if you are confused.
the vertex is on the axis of symmetry. so x=-4
Try taking it from here.
+12 
