can you explain what the equation y = a(x - h)2 + k, a ≠ 0 means and what it represents?
What you typed
y = a(x - h)2 + k, a ≠ 0
a line with slope 2a and y intercept 2 a h + k
is VERY different from
y = a(x - h)^2 + k, a ≠ 0
a parabola with vertex at (h,k) and upright (holds water)