Linear Functions & Graphs
Understand slope, intercepts, and transformations of linear functions.
Practice Problems
Points: (2, 5) and (6, 13)
Slope = 3, y-intercept = -2
Pro Tips & Shortcuts
SAT Tip: Linear functions appear in 20-25% of SAT Math questions, often in word problems.
SAT Tip: Remember: slope = rise over run. Count up/down first, then left/right.
SAT Tip: To quickly graph: plot y-intercept, then use slope to find a second point.
SAT Tip: Always subtract in the same order: (second y - first y) / (second x - first x).
SAT Tip: If you know slope and y-intercept, just plug them into y = mx + b.
The slope tells you how much y changes for each 1-unit increase in x.
Slope is the coefficient of x in y = mx + b form.
From y-intercept, use slope as rise/run to plot the next point.
A slope of 2 means the line goes up 2 for every 1 to the right.
The sign of b is already included, so y = 3x + (-2) = y = 3x - 2.