Linear function
A linear function is a straight line. Enter the slope and the y-intercept — or two points — and see the line, the table and the intercepts.
Your numbers
Answer
The equation
y = 2x − 1
x-intercept
(0.5 ; 0)
y-intercept
(0 ; -1)
How to work it out
- 1y = 2x − 1
- 2x-intercept: 0 = 2x + -1 ⇒ x = 0.5
- 3y-intercept: (0 ; -1)
The formula
y = a · x + b
a is the slope: how much y rises when x increases by 1. b is where the line crosses the y-axis.
a = (y₂ − y₁) / (x₂ − x₁)
The slope from two points on the line.
Table
| x | -3 | -2 | -1 | 0 | 1 | 2 | 3 |
|---|---|---|---|---|---|---|---|
| y | -7 | -5 | -3 | -1 | 1 | 3 | 5 |
More: Equations and functions
- EquationsSolve linear and quadratic equations step by step.
- Scale and ratiosFrom drawing to reality, the rule of three and dividing in a ratio.
- Two equations with two unknownsSolve a system of equations step by step and see the intersection on the graph.
- Growth and decayPercentage growth against linear growth — table, graph and doubling time.