Can you use regression in Desmos on the SAT?

Yes. The Desmos calculator built into the digital SAT's Bluebook app supports tables and regressions, including linear, exponential, and quadratic models.

How do I type the ~ symbol in Desmos?

Press Shift and the key left of 1 on most keyboards, or use the ~ button on Desmos's on-screen keyboard.

What does r² mean in a Desmos regression?

It measures how well the model fits the data, from 0 to 1. A value of 1 means every point lies exactly on the curve; values close to 1 mean a good fit.

Do I need a table, or can I type lists?

Either works. Lists like x_1 = [1, 2, 3] are quicker to type; a table is easier to check for typos.

How to use Desmos regression on the SAT

Updated November 6, 2026

When an SAT question hands you a table of values and asks which equation fits, you could find a slope, test every answer choice, or set up a system. Or you could let Desmos fit the equation for you. That's regression, and the digital SAT's built-in Desmos calculator does it in one line.

This guide shows the setup, which model to use for which kind of data, and four SAT-style examples: a linear table, exponential growth, a parabola through three points, and a prediction from a line of best fit.

The method in three steps

1Enter the data. Either type two lists, like $x_1 = [2, 5, 9]$ and $y_1 = [11, 20, 32]$ (type x_1 for the small 1), or click + and choose table, then type the values in its two columns.
2On a new line, type the model with a tilde ~ in place of the equals sign. For a line: $y_1 \sim m x_1 + b$ .
3Desmos fits the model and shows the values of $m$ and $b$ under that line. Those numbers are your equation.

Pick the model that matches the shape of the data or the answer choices:

Linear: $y_1 \sim m x_1 + b$ . The $y$ -values change by the same amount each step.
Exponential: $y_1 \sim a b^{x_1}$ . The $y$ -values change by the same factor (multiplied) each step.
Quadratic: $y_1 \sim a x_1^2 + b x_1 + c$ . The data rises then falls (or the reverse), or the question names a parabola.

Example 1: which line fits the table?

Linear data

The table shows three values of

x

and their corresponding values of

y

: when

x = 2

y = 11

; when

x = 5

y = 20

; when

x = 9

y = 32

. There is a linear relationship between

x

and

y

. Which equation represents this relationship?

A. $y = 3x + 5$
B. $y = 5x + 3$
C. $y = 3x + 2$
D. $y = 9x - 7$

Type $x_1 = [2, 5, 9]$ and $y_1 = [11, 20, 32]$ , then $y_1 \sim m x_1 + b$ . Desmos shows $m = 3$ and $b = 5$ , with $r^2 = 1$ : a perfect fit.

y_1 \sim m x_1 + b

with

m = 3

b = 5

Answer: A, $y = 3x + 5$

Example 2: exponential growth

Same factor each step

A scientist counts the bacteria in a sample every hour. At

t = 0

hours there are 400 bacteria; at

t = 1

, 600; at

t = 2

, 900; at

t = 3

, 1,350. Which function

N(t)

models the number of bacteria after

t

hours?

A. $N(t) = 400(1.5)^t$
B. $N(t) = 400(0.5)^t$
C. $N(t) = 600(1.5)^t$
D. $N(t) = 400 + 200t$

The counts grow by the same factor each hour, not the same amount, so use the exponential model. Type $x_1 = [0, 1, 2, 3]$ , $y_1 = [400, 600, 900, 1350]$ , then $y_1 \sim a b^{x_1}$ . Desmos shows $a = 400$ and $b = 1.5$ .

y_1 \sim a b^{x_1}

with

a = 400

b = 1.5

Choice D is the trap: a linear model. Try $y_1 \sim m x_1 + b$ and $r^2$ drops below 1, a sign the data isn't linear.

Answer: A, $N(t) = 400(1.5)^t$

Example 3: a parabola through three points

Find a coefficient

The graph of

y = ax^2 + bx + c

, where

a

b

, and

c

are constants, passes through the points

(0, 4)

(1, 3)

, and

(3, 7)

. What is the value of

a

Treat the three points as data. Type $x_1 = [0, 1, 3]$ , $y_1 = [4, 3, 7]$ , then $y_1 \sim a x_1^2 + b x_1 + c$ . Desmos shows $a = 1$ , $b = -2$ , and $c = 4$ .

y_1 \sim a x_1^2 + b x_1 + c

Three points fix a parabola exactly, so the fit is perfect. By hand, this is a system of three equations. Desmos skips all of it.

Answer: $1$

Example 4: predict from a line of best fit

Messy data

Five students reported hours studied and test scores: 1 hour, 62; 2 hours, 67; 3 hours, 71; 4 hours, 78; 5 hours, 82. Based on a line of best fit for these data, which is closest to the predicted score for a student who studies 7 hours?

A. 85
B. 88
C. 92
D. 97

Type the lists and $y_1 \sim m x_1 + b$ . This time the points aren't on one line, so Desmos finds the best fit: $m = 5.1$ and $b = 56.7$ , with $r^2 \approx 0.99$ .

best fit:

m = 5.1

b = 56.7

Now use the fitted values directly: on a new line, type $m \cdot 7 + b$ . Desmos shows $92.4$ .

Answer: C, 92

Mistakes that cost points

Typing = instead of ~. $y_1 = m x_1 + b$ asks Desmos for sliders, not a fit. The tilde is what tells it to fit.
Lists of different lengths. Every $x$ needs a $y$ . If Desmos shows an error, count the entries.
The wrong model. Equal differences mean linear; equal ratios mean exponential. If $r^2$ isn't close to 1, try another model.
Rounding too early. Desmos displays rounded values. Type $m$ and $b$ themselves into later calculations instead of retyping the decimals.

Practice this move

Practice on real SAT-style problems

Intersect Prep puts the same Desmos calculator beside 16 SAT-style problems that use this move, with a step-by-step strategy for each one. Create a free account to try a full lesson with the calculator; a pass unlocks the rest.

Try a free lesson See pricing

Questions

Can you use regression in Desmos on the SAT?: Yes. The Desmos calculator built into the digital SAT's Bluebook app supports tables and regressions, including linear, exponential, and quadratic models.
How do I type the ~ symbol in Desmos?: Press Shift and the key left of 1 on most keyboards, or use the ~ button on Desmos's on-screen keyboard.
What does r² mean in a Desmos regression?: It measures how well the model fits the data, from 0 to 1. A value of 1 means every point lies exactly on the curve; values close to 1 mean a good fit.
Do I need a table, or can I type lists?: Either works. Lists like x_1 = [1, 2, 3] are quicker to type; a table is easier to check for typos.

SAT is a trademark registered by the College Board, which is not affiliated with, and does not endorse, this site. Desmos is a trademark of Desmos Studio PBC.

How to use Desmos regression on the SAT

Updated November 6, 2026

The method in three steps

1Enter the data. Either type two lists, like $x_1 = [2, 5, 9]$ and $y_1 = [11, 20, 32]$ (type x_1 for the small 1), or click + and choose table, then type the values in its two columns.
2On a new line, type the model with a tilde ~ in place of the equals sign. For a line: $y_1 \sim m x_1 + b$ .
3Desmos fits the model and shows the values of $m$ and $b$ under that line. Those numbers are your equation.

Pick the model that matches the shape of the data or the answer choices:

Linear: $y_1 \sim m x_1 + b$ . The $y$ -values change by the same amount each step.
Exponential: $y_1 \sim a b^{x_1}$ . The $y$ -values change by the same factor (multiplied) each step.
Quadratic: $y_1 \sim a x_1^2 + b x_1 + c$ . The data rises then falls (or the reverse), or the question names a parabola.

Example 1: which line fits the table?

Linear data

The table shows three values of

x

and their corresponding values of

y

: when

x = 2

y = 11

; when

x = 5

y = 20

; when

x = 9

y = 32

. There is a linear relationship between

x

and

y

. Which equation represents this relationship?

A. $y = 3x + 5$
B. $y = 5x + 3$
C. $y = 3x + 2$
D. $y = 9x - 7$

Type $x_1 = [2, 5, 9]$ and $y_1 = [11, 20, 32]$ , then $y_1 \sim m x_1 + b$ . Desmos shows $m = 3$ and $b = 5$ , with $r^2 = 1$ : a perfect fit.

y_1 \sim m x_1 + b

with

m = 3

b = 5

Answer: A, $y = 3x + 5$

Example 2: exponential growth

Same factor each step

A scientist counts the bacteria in a sample every hour. At

t = 0

hours there are 400 bacteria; at

t = 1

, 600; at

t = 2

, 900; at

t = 3

, 1,350. Which function

N(t)

models the number of bacteria after

t

hours?

A. $N(t) = 400(1.5)^t$
B. $N(t) = 400(0.5)^t$
C. $N(t) = 600(1.5)^t$
D. $N(t) = 400 + 200t$

y_1 \sim a b^{x_1}

with

a = 400

b = 1.5

Choice D is the trap: a linear model. Try $y_1 \sim m x_1 + b$ and $r^2$ drops below 1, a sign the data isn't linear.

Answer: A, $N(t) = 400(1.5)^t$

Example 3: a parabola through three points

Find a coefficient

The graph of

y = ax^2 + bx + c

, where

a

b

, and

c

are constants, passes through the points

(0, 4)

(1, 3)

, and

(3, 7)

. What is the value of

a

Treat the three points as data. Type $x_1 = [0, 1, 3]$ , $y_1 = [4, 3, 7]$ , then $y_1 \sim a x_1^2 + b x_1 + c$ . Desmos shows $a = 1$ , $b = -2$ , and $c = 4$ .

y_1 \sim a x_1^2 + b x_1 + c

Three points fix a parabola exactly, so the fit is perfect. By hand, this is a system of three equations. Desmos skips all of it.

Answer: $1$

Example 4: predict from a line of best fit

Messy data

A. 85
B. 88
C. 92
D. 97

Type the lists and $y_1 \sim m x_1 + b$ . This time the points aren't on one line, so Desmos finds the best fit: $m = 5.1$ and $b = 56.7$ , with $r^2 \approx 0.99$ .

best fit:

m = 5.1

b = 56.7

Now use the fitted values directly: on a new line, type $m \cdot 7 + b$ . Desmos shows $92.4$ .

Answer: C, 92

Mistakes that cost points

Typing = instead of ~. $y_1 = m x_1 + b$ asks Desmos for sliders, not a fit. The tilde is what tells it to fit.
Lists of different lengths. Every $x$ needs a $y$ . If Desmos shows an error, count the entries.
The wrong model. Equal differences mean linear; equal ratios mean exponential. If $r^2$ isn't close to 1, try another model.
Rounding too early. Desmos displays rounded values. Type $m$ and $b$ themselves into later calculations instead of retyping the decimals.

Practice this move

Practice on real SAT-style problems

Try a free lesson See pricing

Questions

Can you use regression in Desmos on the SAT?: Yes. The Desmos calculator built into the digital SAT's Bluebook app supports tables and regressions, including linear, exponential, and quadratic models.
How do I type the ~ symbol in Desmos?: Press Shift and the key left of 1 on most keyboards, or use the ~ button on Desmos's on-screen keyboard.
What does r² mean in a Desmos regression?: It measures how well the model fits the data, from 0 to 1. A value of 1 means every point lies exactly on the curve; values close to 1 mean a good fit.
Do I need a table, or can I type lists?: Either works. Lists like x_1 = [1, 2, 3] are quicker to type; a table is easier to check for typos.