Read off coordinates, spot where a function changes sign, or check a value without algebra.
In short: A table of values lists the outputs of a function for chosen inputs, generated by the GDC from the function you have entered. You choose a start value and a step, and the calculator fills in the table. Use it to sketch a graph, to spot where the sign changes, or to check values quickly.
| TI-84 Plus CE | Casio fx-CG50 and fx-CG100 | TI-Nspire CX | |
|---|---|---|---|
| Key sequence | 2nd → WINDOW (TBLSET) to set the start and step, then 2nd → GRAPH (TABLE) to view it. | Enter the function in Table mode, set the range, then TABL (F6). | Add a Graphs or Lists & Spreadsheet page, then menu → Table (or ctrl+T). |
Tip: Use a small step (e.g. 0.1) to pin down a root or a maximum more precisely.
Tip: Use a small step (e.g. 0.1) to pin down a root or a maximum more precisely.
Tip: Use a small step (e.g. 0.1) to pin down a root or a maximum more precisely.
Here's a real IB-style question that uses exactly this technique.
For f(x) = x³ − 3x − 1, use a table to find an interval of width 1 in which a root lies, for x > 0.
Read off coordinates, spot where a function changes sign, or check a value without algebra. Spotting where a function changes sign, to locate a root before solving exactly. Reading off several coordinates at once without repeated substitution.
1. Enter the function in the Y= / graph editor. 2. 2nd → WINDOW (TBLSET) to set the start and step, then 2nd → GRAPH (TABLE) to view it. 3. A sign change between two rows means a root lies between those x-values.
1. Enter the function in the Y= / graph editor. 2. Enter the function in Table mode, set the range, then TABL (F6). 3. A sign change between two rows means a root lies between those x-values.
1. Enter the function in the Y= / graph editor. 2. Add a Graphs or Lists & Spreadsheet page, then menu → Table (or ctrl+T). 3. A sign change between two rows means a root lies between those x-values.
Use a small step (e.g. 0.1) to pin down a root or a maximum more precisely.
In the worked example on this page (2 marks, Paper 2), the marks are: M1: Table showing f(1) and f(2) with opposite signs; A1: Root between x = 1 and x = 2.
Questions that need this technique link back to this guide. Try one in practice mode, or see every GDC guide.