This document provides instructions for sketching linear functions from their equations in gradient-intercept form. It gives examples of sketching linear graphs using x- and y-intercepts. It also explains how to enter linear equations into a TI-Nspire CAS calculator to draw their graphs, and how to use the calculator to find the y-intercept.

1. Sketching linear functions
The general form for linear equations (gradient–intercept form):
To sketch a graph from an equation
expressed in general form, follow these
steps.
Example 1.
𝑦 = 4𝑥 + 3
𝑦 = 𝑚𝑥 + 𝑐
𝑟𝑖𝑠𝑒 4
∴ 𝑔𝑟𝑎𝑑𝑖𝑒𝑛𝑡 = 𝑚 =
= =4
𝑟𝑢𝑛 1
𝑦 − 𝑖𝑛𝑡𝑒𝑟𝑐𝑒𝑝𝑡 = 𝑐 = 3

2. sketching linear graphs using intercepts
Example 2.
𝒙 𝒊𝒏𝒕𝒆𝒓𝒄𝒆𝒑𝒕 𝒚 = 𝟎
0 = 2𝑥 + 1
1
𝟏
∴ 𝑥 = − 𝑝𝑜𝑖𝑛𝑡 → − , 𝟎
2
𝟐
𝒚 𝒊𝒏𝒕𝒆𝒓𝒄𝒆𝒑𝒕 𝒙 = 𝟎
𝑦 = 2 0 + 1 = 1 𝑝𝑜𝑖𝑛𝑡 → (𝟎, 𝟏)

3. Equations and functions and the CAS calculator
When you are using the TI-Nspire CAS calculator to draw the graphs of
functions, the equations must be entered into the calculator using fn(x)
On a Graphs page, complete the function
entry line as:
f 1(x) = 2x + 1
Then press ENTER· to draw the graph.
To find the y-intercept, press:
• Menu b
• 5:Trace 5
• 1:Graph Trace 1
The y-intercept will be displayed.
Press ENTER · to lock the coordinates
into place.

4. Example 3.
Exercise 1D