Graphing Calculator

Free online graphing calculator. Plot linear equations, quadratic curves, and functions on a coordinate grid. No download needed.

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Graph a Function

Comprehensive Guide & Practice

Master the mathematical principles, formulas, and step-by-step methods with worked examples and FAQs.

1. How to Use the Graphing Calculator

Type any mathematical function using x as the variable. Use ^ for powers (e.g. x^2), * for multiplication, and standard math notation. Press Plot to draw it. You can plot multiple equations at once — each gets a distinct colour.

2. Linear Equations: y = mx + b

The most common function to graph is a linear equation in slope-intercept form: y = mx + b. Here, m is the slope (how steep the line is) and b is the y-intercept (where the line crosses the y-axis).

y = 2x + 1 — slope of 2, crosses y-axis at (0, 1)
y = -x + 4 — downward slope of 1, y-intercept at 4
y = 0.5*x — gentle positive slope through the origin

3. Quadratic Equations: Parabolas

Quadratic equations produce U-shaped curves called parabolas. Standard form: y = ax² + bx + c. Try plotting x^2 - 4 or -x^2 + 3 to see upward and downward parabolas.

4. Other Functions You Can Plot

x^3 - x — cubic polynomial
x^2 + 2*x + 1 — complete quadratic
1/x — hyperbola (undefined at x=0)
2*x - 5 — linear with negative y-intercept

See also: Equation Solver | Quadratic Solver | Algebra Basics