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Square
The square function is also known as the quadratic function, the second degree function, or simply called a parabola.
Definition
The bare quadratic function has the form: \[ f(x)=x^2. \]
Properties
- Inverse of $\sqrt{x}$.
- Never negative: $x^2 \geq 0$, for all $x\in \mathbb{R}$.
- The quadratic function is two-to-one since it sends both $x$ and $-x$ to $x^2=(-x)^2$.
- The quadratic function is convex, i.e., it curves upwards.