Quadratic Functions and Transformations
The parent quadratic function is p(x)=x2, which forms a basic parabola. This U-shaped curve has its vertex at the origin (0,0). Every quadratic function's domain includes all real numbers (-∞, ∞), while its range for the parent function is [0, ∞), meaning values never go below zero.
When we transform quadratic functions, we can shift, stretch, compress, or flip them. For example, in g(x)=−(x−2)2, the negative sign flips the parabola downward, while the x−2 shifts it right by 2 units. These transformations follow the same rules we learned earlier but applied to parabolas.
The position of the numbers in the formula tells you exactly what transformation to apply. Numbers inside the squared expression affect horizontal movement, while numbers outside affect vertical stretching or compression. Adding or subtracting at the end shifts the entire parabola up or down.
Quick Tip: When matching equations to graphs, identify the vertex position first (the h,k values), then check if the parabola opens up or down (the sign of a). This immediately narrows down your options!