Using Desmos for the Digital SAT(And Hidden Desmos Functions)

If you're taking the Digital SAT, you’ll have access to the built-in Desmos graphing calculator. But are you really making the most of it? This guide walks you through everything you need to know about Desmos' functionalities—so you can navigate it with confidence on test day.

Getting Started with Desmos

When you first open Desmos on the Digital SAT, you'll see a blank graphing space and an expression entry panel. Simply start typing an equation, and the graph will update instantly. You can enter multiple expressions, undo and redo changes (Ctrl + Z and Ctrl + Y), and adjust your view with zoom and pan functions. If you're new to Desmos, take a few minutes to explore Desmos Testing Mode before test day.

Graphing Equations Like a Pro

Desmos allows you to visualize almost any function by typing it directly into the expression list. Whether you're working with linear equations (y = 2x + 3), quadratic functions (y = x^2 - 4x + 3), or inequalities (y ≤ 2x + 1), Desmos can handle it all. You can even graph polar functions (r = sin(θ)) and parametric equations (x = t, y = t^2).

One of the best features? You can type out expressions naturally. For example, theta gives you θ, and sqrt gives you a square root symbol (√). Unlike traditional calculators, Desmos makes it easy to enter and manipulate functions.

Using Tables for Quick Data Analysis

Got a question that requires organizing numbers into a table? Desmos lets you create and analyze data tables in seconds. Click the + sign, select Table, and enter your x- and y-values. This is super helpful for spotting patterns, finding averages, and even running regression models. Want to find the best-fit line? Just type y ~ mx + b, and Desmos will calculate the equation for you.

Sliders: The Secret to Interactive Learning

If you enter an equation with an undefined variable (like y = mx + b), Desmos gives you the option to add a slider. Adjust it in real-time to see how changing variables affect a function. This is a game-changer when studying transformations, slope-intercept relationships, or system solutions.

To customize a slider’s range, click the values at the ends and set new limits. This is useful for restricting values when testing inequalities or modeling real-world data.

Solving Equations and Systems with Ease

Forget solving systems of equations by hand—Desmos makes it effortless. Simply enter two equations, and the graph will highlight their intersection point (the solution). This works for:

• Linear systems (y = 2x + 1 and y = -x + 4)
• Absolute value equations (|x - 4| = 9)
• Quadratic and linear intersections (y = x^2 and y = 3x + 5)

For absolute value equations, click the keyboard icon and use the abs function—or just type abs(x - 4) = 9 directly!

Making Statistics Simple

Desmos isn’t just for graphing. Need to find the mean, median, or standard deviation of a data set? Type your numbers into brackets like [2, 5, 9, 10, 18, 20] and use the built-in statistical functions:

• mean([list]) – Finds the average
• median([list]) – Finds the middle value
• stdev([list]) – Calculates standard deviation

This is especially useful for SAT problems involving data interpretation.

Graphing Circles and Other Shapes

For conic sections like circles, Desmos lets you enter equations in standard form. To graph a circle centered at (2,5) with radius 5, just type:

(x - 2)^2 + (y - 5)^2 = 25

You’ll see a perfect circle appear instantly. You can do the same for ellipses and hyperbolas using their respective equations.

Hidden Desmos Functions You Need to Know

While most common functions are available under the Functions menu, Desmos also supports several hidden shortcuts that make typing math easier. Here are a few you should know:

• abs(x) → Absolute value (also found under Functions → Misc)
• theta → θ (useful for polar coordinates)
• pi → π
• sqrt(x) → √x
• nthroot(x, n) → nth root of x
• sum(list) → Sum of all elements in a list
• prod(list) → Product of all elements in a list
• mod(a, b) → Modulus (remainder of a/b)
• ceil(x) → Rounds up
• floor(x) → Rounds down

These shortcuts will save you time on the SAT and help you focus on solving problems instead of hunting through menus.

Mastering Desmos Keyboard Shortcuts

Speed matters, especially on a timed test. Here are some keyboard shortcuts that can make navigating Desmos a breeze:

• Ctrl + S – Save your graph
• Ctrl + Z / Ctrl + Y – Undo/Redo
• Shift + Drag – Adjust graphing window
• Arrow keys – Move between expressions

Using these shortcuts can make your test-day experience much smoother.

Final Thoughts: Why Desmos is Your Best Friend on Test Day

Desmos isn’t just a calculator—it’s a powerful problem-solving tool that can save you valuable time. The best way to prepare? Practice using it regularly so that navigating it on the SAT feels second nature. Head over to Desmos Testing Mode and start experimenting with its features. The more comfortable you are, the more efficiently you’ll be able to tackle SAT math questions!

Looking for more advanced usage of Desmos? Check out our Essential Desmos Tips & Tricks to maximize your score!