SAT Math Desmos Masterclass Vocabulary

Vocabulary terms and foundational concepts for mastering the Desmos graphing calculator on the digital SAT Math section.

Blue Book Decimal Entry Rule

The official protocol allowing students to enter decimals into free-response boxes by truncating, rounding the last digit, or entering a fraction; the recommended approach is typing digits until the input field stops accepting them.

SAT Regression Technique

The method of using Desmos regression capabilities not for traditional statistical analysis, but to solve directly for unknown coefficients, slopes, intercepts, or constants ($a$, $b$, $c$) defining a mathematical function.

Solution to a System of Equations

The graphical point or points of intersection where two or more distinct functions touch or cross each other on the coordinate plane.

Left Hand Side / Right Hand Side (LHS / RHS) Method

A technique for solving single-variable equations by graphing $y = \text{left hand side}$ and $y = \text{right hand side}$ as separate functions, where the $x$-values of the intersection points represent the solutions.

Desmos Slider

An interactive tool in Desmos that allows an unknown constant or parameter to be adjusted across a numerical range to locate specific intersection conditions or determine values.

Discriminant

An algebraic hand-solving method used for quadratic equations to determine intersection counts when Desmos sliders cannot provide exact fractional values.

Solution to a System of Inequalities

The overlapping shaded region on a Desmos graph that includes every coordinate point simultaneously satisfying all inequalities in the system.

Equivalent Expressions Method

A testing technique where an original algebraic expression and each candidate answer choice are graphed simultaneously to verify which choice maps to the exact same curve.

Tilde ($\sim$)

The keyboard symbol used in Desmos in place of an equals sign to execute a regression model between variables or expressions.

Custom Regression

A user-specified Desmos regression format (such as $y_1 \sim \frac{a}{x_1 - b}$) configured using table columns to determine non-standard or arbitrary functional parameters.

Element List

A bracketed list structure (such as $x_1 = [1 \dots 5]$) used in Desmos to plug multiple values into a regression or solve multi-equation systems simultaneously in a single command.

nthroot Command

A built-in Desmos keyboard shortcut typed to compute radicals of any specified index beyond square root (sqrt) and cube root (cbrt).

Regression Single-Solution Limitation

The property of Desmos regressions wherein the software outputs only one valid parameter set or solution (such as returning only the positive root for $x_1^2 \sim 16$) even when multiple mathematical solutions exist.

Circle Endpoints in Desmos

The gray coordinate dots located at the top and bottom extremes of a graphed circle that represent the true diameter boundaries, as opposed to $x$-intercepts which may not span the full diameter.

Degree Mode Toggle

The calculator setting that must be actively selected to calculate trigonometric expressions (such as $\sin(60)$ degrees), because Desmos defaults to radian mode.

savemedesmos.com

A specialized practice web application featuring $27$ ordered questions designed to test each Desmos technique covered throughout the lecture.