# the top of a parabola

## Introduction

Empty Input Boxes can be used to insert the coordinates of a point in the same way as to type the result of a calculation. You only have to respect the appropriate syntaxes for points. In this worksheet we show the difference. Additionally we'll show some aternative ways to deal with randon numbers.

## How to do this

• parameters of parabola y = a (x - p)² + q: - factor a: Define the number a as a random number between -2 and 2 except 0 with the commands: `lista = Shuffle({-2, -1, 1, 2})` and `﻿````a = lista(1) ```- p and q: Define `p = RandomBetween(-4, 4)` and `q = RandomBetween(-4, 4)`.
• Solution: define a point Sol by using a capital to make sure it is a point and not a vector! `Sol = (p, q)`
• The equation: We'll show the equation of the parabola in the form ax² + bx + c. Define `f(x) = Polynomial(a (x - p)²`` + q)` and use f in a dynamic text to show the equation of the parabola in the form ax² + bx + c.
• Answer: define a number Ans to use as anwer and give it a value, that's certainly not the solution. Ans = (pi, pi). Again use a capital!
• The rest goes exactly the same as when working with numbers instead of points.