The vertex of a quadratic function is (6, 2), and the y-intercept of the function is (0, −70). the equation of the function in vertex form, f(x) = a(x - h)2 + k, is shown. –70 = a(0 – 6)2 + 2 what is the value of a?

To answer the question above, make use of the given equation of the parabola,
                                        f(x) = a(x - h)² + k
where h and k are the abscissa and ordinate or the given vertex. Substituting,
                                        f(x) = a(x - 6)² + 2
To solve for the value of a, substitute the coordinates of the point (0, -70) to x and y. 
                                        -70 = a(0 - 6)² +2
The value of a is -2.