SAT Math · Study & Practice

Linear Functions

Linear functions and lines are central to the SAT — slope, intercepts and the forms of a line appear throughout the Algebra domain. This chapter covers slope, rate of change, the slope formula, the equation of a line, and the point-slope, slope-intercept and standard forms. Read each topic, try the problems with the hint ladder, then take the 8-question topic test.

Topics

1 Slope 4 worked · 5 practice · 8-Q test Start → 2 Rate of Change 4 worked · 5 practice · 8-Q test Start → 3 Slope Formula 4 worked · 5 practice · 8-Q test Start → 4 Equation of Line 4 worked · 5 practice · 8-Q test Start → 5 Point-Slope Form 4 worked · 5 practice · 8-Q test Start → 6 Slope-Intercept Form 4 worked · 5 practice · 8-Q test Start → 7 Standard Form 4 worked · 5 practice · 8-Q test Start →

Chapter test

📝 Linear Functions — Chapter Test

25 fresh questions · timed · full solutions

Start chapter test →

📊 My SAT analytics

Track scores, accuracy by topic and progress over time.

View analytics →

Formula Reference Sheet

This chapter

Slope

Slope formula	m = (y₂ − y₁)/(x₂ − x₁)
Meaning	rise over run; rate of change
Parallel lines	equal slopes
Perpendicular lines	slopes multiply to −1

Forms of a line

Slope-intercept	y = mx + b
Point-slope	y − y₁ = m(x − x₁)
Standard	Ax + By = C
y-intercept	value of y when x = 0

Digital SAT reference

Area & Circumference

Circle area	A = πr²
Circle circumference	C = 2πr
Rectangle	A = ℓw
Triangle	A = ½ b h

Volume

Rectangular box	V = ℓwh
Cylinder	V = πr²h
Sphere	V = 4⁄3 πr³
Cone	V = 1⁄3 πr²h
Pyramid	V = 1⁄3 ℓwh

Right triangles

Pythagorean theorem	a² + b² = c²
30°–60°–90°	sides x : x√3 : 2x
45°–45°–90°	sides s : s : s√2

Constants

Degrees in a circle	360°
Radians in a circle	2π
Angles of a triangle	sum = 180°