# Function graphs

## Introduction

There are two ways to create graphs in the Geometry & Graphs question type:

- By plotting a formula
- By drawing a curve through the Graph tool.

## Plotting a formula

Use the Formula button in the bottom line of the toolbar to enter the formula you want to display. The expected form is $y=expression$, where $expression$ depends on $x$.

Implicit formulas, like $x^2 + y^2 = 1$, are currently not allowed. We will add support for such formulas soon.

*Figure: A graph used as part of a construction to illustrate the concept of finite differences and tangents.*

You can work with the graph like any other element in the canvas. For instance, you can adjust the style of the graph line in the element panel. You can also position glider points on the graph or put a point on the intersection of the graph with other elements.

## Using the Graph tool

The Graph tool allows you to draw a smooth curve through a sequence of points. We discussed this tool in the Geometrical Constructions section.

*Figure: A graph created with the Graph tool. You can drag the points or use the Graph tool to add additional points to the graph.*