patterns: vertical : y = a(x - h)² + k horizontal: x = a(y - k)² + h
Look at the patterns above and remember these key points.
1) if the x is squared, the parabola is vertical. It either opens up or down.
if the y is squared, the parabola is horizontal. It either opens left or right.
2) if a is positive, the parabola opens up or to the right.
if a is negative, the parabola opens down or to the left
3) the vertex is at (h,k). Be very careful. locations of h and k varies if the parabola is vertical or horizontal. its sign is also different in those positions