How to make a table of values on Desmos

A table is the quiet workhorse of the digital SAT calculator. When a question hands you specific inputs, or asks which equation produces a set of points, a table answers it in seconds — no algebra, no guessing.

In the SAT's Desmos calculator, click the + button (top-left) and choose Table. Type your x-values down the first column, then define the second column as a function of the first — either type a formula with x_1 (like 2x_1^2-3) or define f(x)=… on its own line and enter f(x_1). Desmos fills in every output. Use it to evaluate f(a) at chosen inputs, match a table to an equation, or find where a function reaches a target value.

Practice this on SAT-style Math All Desmos techniques

Desmos table: Make the mathematical object in this brief the hero: a Desmos expression list: a defined function row f(x)=… above a two-column table headed x_1 and f(x_1) , four rows of filled-in outputs, the points plotted as dots on a small grid to the right

+ → TableThe table lives behind the plus menu, top-left of the list.

x_1 columnThe first column is your inputs; the second can hold a formula.

Auto outputsDefine the second column with x_1 and Desmos computes each row.

Points appearEvery (x, y) row also plots as a dot you can see and click.

Step by step

Build a table that fills itself in

Four steps from a blank calculator to a column of exact outputs. Once you've done it a few times it takes under fifteen seconds.

Step 1

Open the table

Click the + at the top-left of the expression list and pick Table. A two-column table appears with headers x_1 and y_1.

Step 2

Type your inputs

In the first column, enter the x-values you care about, one per row — for example -1, 0, 2. Press Enter or the down arrow to add rows.

Step 3

Define the output column

Click the second-column header and replace y_1 with a formula in x_1, such as 2x_1^2-3. Or define f(x)=2x^2-3 on a separate line and type f(x_1) in the header.

Step 4

Read the outputs

Desmos computes each row instantly. Read off any f(a) you need, and glance at the plotted dots on the grid to sanity-check the shape.

Make it automatic on real questions.

The setup only sticks if you use it. Practice tables on SAT-style Math with the built-in calculator until you stop thinking about the keystrokes.

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Worked example

A table that does two jobs at once

Evaluate a function, then match a table

SAT-style problem. The function is defined by f(x) = 2x² − 3. First find f(−1), f(0) and f(2). Then decide which of the tables below could represent the same function f.

Candidate tables (one row may be wrong on purpose):
A. (−1, −1), (0, −3), (2, 5) · B. (−1, −5), (0, −3), (2, 5) · C. (−1, −1), (0, 3), (2, 5)

In Desmos, define f(x)=2x^2-3 on one line. Add a table, type -1, 0, 2 in the first column, and set the header of the second column to f(x_1). Desmos fills in −1, −3, 5.

Now compare. The three computed pairs are (−1, −1), (0, −3), (2, 5). Table A matches every row exactly. Table B is wrong at x = −1 (it lists −5, but 2(−1)²−3 = −1); Table C is wrong at x = 0 (it lists 3, but f(0) = −3).

Why the table beats algebra here

Plugging x = −1 into 2x² − 3 by hand is where careless errors live: forget that (−1)² = +1 and you "confirm" the wrong table. The table removes the squaring-sign trap entirely — Desmos returns f(−1) = −1, f(0) = −3, f(2) = 5 with no chance of a sign slip.

Answer: A. To find where a function hits a value instead, add a row of x-values and scan the output column for the target — or graph y = 2x²−3 with y = (target) and click the intersection.

When to use / pitfalls

Reach for a table — or don't

Use it

When inputs are handed to you.

"Find f(3)", "complete the table", or "which equation produces these points" are textbook table questions. Type the inputs, define the formula, read the column.

Use it

To spot a pattern fast.

Seeing outputs line up — constant differences (linear), constant ratios (exponential), or a symmetric dip (quadratic) — often reveals the answer before you finish reading the choices.

Watch out

For subscripts and exact targets.

The column variable is x_1 (type x, then _, then 1) — plain x won't link. And if a target falls between rows, switch to a graph and click the intersection rather than guessing from the table.

FAQ

Desmos tables on the SAT, answered

How do I add a table in the Desmos SAT calculator?

Click the plus (+) button at the top-left of the expression list, then choose Table. Desmos drops in a two-column table with headers x_1 and y_1. Type your x-values down the first column; the second column can hold numbers or a formula written in terms of x_1.

How do I make Desmos fill in the outputs automatically?

Either define a function on its own line first — for example f(x)=2x^2-3 — and type f(x_1) in the table's second-column header, or type the formula directly using x_1, such as 2x_1^2-3. As you enter x-values, Desmos computes each output in the next column.

Can a Desmos table tell me which equation matches a set of points?

Yes. Type the given input/output pairs into a table, then enter each candidate equation on its own line and add a matching table or graph for it. The equation whose outputs match every given pair is the answer. You can also see the typed points appear as dots on the graph.

How do I find where a function equals a target value with a table?

Enter a column of x-values, fill the output column with your function, and scan for the row whose output equals the target. If the value falls between two rows, add closer x-values to zoom in, or graph the function alongside y = target and click the intersection for an exact answer.

Do I have to use a table, or can I just graph?

Both work. A table is fastest when a question hands you specific inputs or a list of points to check. Graphing is better when you need an intersection, a vertex or a region. Many students build a table to read exact outputs and keep a graph open to confirm the shape.

Turn Desmos into points.

Start free and practice SAT-style Math with the built-in calculator, until tables and graphs are automatic.

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