PrepPros Complete Guide to Digital SAT Math Vocabulary

Comprehensive vocabulary flashcards covering the essential math concepts, formulas, and test-taking strategies for the Digital SAT Math section.

Backsolving

A test-taking technique where you plug the answer choices back into the original equation to find which one makes the statement true.

Substitution (Technique)

Replacing variables in a question with simple numbers (like 1, 2, or 10) to make complex algebraic expressions easier to evaluate.

Equivalent Expressions

Different mathematical forms that represent the same value for all inputs; their graphs in Desmos are identical.

PEMDAS

The acronym for order of operations: Parentheses, Exponents, Multiplication and Division (left-to-right), Addition and Subtraction (left-to-right).

Extraneous Solution

A result obtained from algebraic solving that does not actually satisfy the original equation when plugged back in, common with square roots and denominators.

Slope

The measure of steepness represented as \text{rise/run} or \frac{y_1 - y_2}{x_1 - x_2}.

Parallel Lines

Lines in the same plane that never intersect because they have the same slope.

Perpendicular Lines

Lines that intersect at a 90^{\circ} angle; their slopes are negative reciprocals of each other (m_1 \times m_2 = -1).

Standard Form (Line)

The equation of a line written as Ax + By = C.

Slope-Intercept Form

The equation of a line written as y = mx + b, where m is the slope and b is the y-intercept.

Vertex of a Parabola

The maximum or minimum point of a quadratic function; located at (h, k) in vertex form y = a(x - h)^2 + k.

Discriminant

The part of the quadratic formula under the radical, b^2 - 4ac, used to determine the number of real solutions.

Exponential Growth

A model where a quantity increases by a fixed percentage over time, represented by A = P(1 + r)^t where r > 0.

Exponential Decay

A model where a quantity decreases by a fixed percentage over time, represented by A = P(1 - r)^t where 0 < r < 1.

SOH-CAH-TOA

A mnemonic for right triangle trigonometry: \sin(\theta) = \frac{\text{Opposite}}{\text{Hypotenuse}}, \cos(\theta) = \frac{\text{Adjacent}}{\text{Hypotenuse}}, and \tan(\theta) = \frac{\text{Opposite}}{\text{Adjacent}}.

Complementary Angles Identity

The trigonometric rule stating that \sin(x) = \cos(90^{\circ} - x) and \cos(x) = \sin(90^{\circ} - x), meaning sine and cosine of complementary angles are equal.

Radians

A unit of angular measure where \pi\text{ radians} = 180^{\circ}; used to calculate arc length and sector area.

Standard Deviation

A measure of the spread of values in a data set; data points closer to the mean result in a lower value.

Margin of Error

A statistic expressing the range within which the true population mean is likely to fall based on a sample.

Median

The middle value in a data set when the numbers are ordered from smallest to largest.

Arc Length

A portion of the circumference of a circle, calculated by \frac{\theta}{360} \times 2\pi r.

Sector Area

A portion of the total area of a circle, calculated by \frac{\theta}{360} \times \pi r^2.

Difference of Squares

A special quadratic form (x + y)(x - y) = x^2 - y^2.

Box and Whisker Plot

A visual representation of data showing the minimum, first quartile, median, third quartile, and maximum.