# Plotting Curves with a Graphical Calculator

## (Functions & Calculators - Part 1)

Graphical calculators help us to quickly plot the points of a function's curve.

Given a domain (or an interval of $$x$$ values) over which we wish to study a function and its curve, a calculator is capable of plotting hundreds of points at a speed that we could never match otherwise.

Nevertheless, it is important to keep in mind that all that a calculator does is construct its very own table of values, just as we would do by hand.

### What we'll Learn

• How to plot a function's curve, given its equation.
• How to adjust the calculator's window settings so we can see the curve properly.
• How to find the coordinates of a curve's $$x$$-intercepts (where it cuts the $$x$$-axis).
• How to find the coordinates of a curve's maximum or minimum (sometimes curves have more than one).
Each of these things is taught witch tutorials, in which we use the TI Nspire CX, but the method will be similar with all texas Intruments Calculators and any other major brand.

## Plotting a Curve and Adjusting Window Size

Given a function, $$f(x)$$, or a curve's equation $$y=f(x)$$, our starting point is to learn how to plot this on our calculator.

We learn how to do this in the following tutorial.

## Tutorial

In the following tutorial we plot the curve of $$f(x) = x^3-7x+6$$, for $$-4\leq x \leq 4$$.

We learn two things:

• How to plot the curve.
• How to adjust the window size to see the curve properly.

## Finding Maximum & Minimum Points

The next skill we need to know with the calculator is how to find the coordinates of any maximum or minimum points on a curve.

We learn how to do this in the tutorial below.

## Tutorial

Plot the curve $$f(x) =$$ for $$-4\leq x \leq 4$$ and find the coordinates of any maximum or minimum points..

## Finding $$x$$-intercepts

The last skill we learn about on this page, with the calculator, is how to find the coordinates of any $$x$$-intercepts, those are the points at which the curve cuts, or crosses, the $$x$$-axis.

We learn how to do this in the tutorial below.

## Tutorial

1. Plot the curve $$f(x) = x^2-4x$$ for $$-3\leq x \leq 7$$ and find the coordinates of any $$x$$-intercepts it may have.
2. Plot the curve $$f(x) =$$ for $$-4\leq x \leq 4$$ and find the coordinates of any $$x$$-intercepts it may have.