Graphing Calculator

About the Graphing Calculator

Plot any function y = f(x) on an interactive Cartesian grid. Supports +, -, *, /, ^, parentheses and functions like sin, cos, tan, sqrt, log, ln, abs, exp.

How to use this calculator

1. Type a function in terms of x, such as y = 2x + 3 or y = x^2 - 4.
2. Use the graph to see the shape, intercepts, and key features of the function.
3. Change the formula to compare different functions on the same grid if the tool allows it.
4. Check a few points by hand to make sure the graph matches the equation.

The formula explained

This tool graphs equations written as y = f(x), which means the value of y depends on the value of x. Each x-value you choose gives one point on the graph, and connecting all those points shows the function’s shape.

• x = the input value, shown on the horizontal axis
• y = the output value, shown on the vertical axis
• f(x) = the function rule that gives the y-value for each x

Step by step method

1. Start with the formula and choose several x-values, such as -2, -1, 0, 1, and 2.
2. Substitute each x-value into the rule to find the matching y-values.
3. Plot the points on the grid and notice the pattern they form.

Worked example

Problem. Graph the function y = x^2 - 4 and identify a few points on the curve.

1. Choose x = -2, -1, 0, 1, 2.
2. Compute the outputs: y = (-2)^2 - 4 = 0, y = (-1)^2 - 4 = -3, y = 0^2 - 4 = -4, y = 1^2 - 4 = -3, y = 2^2 - 4 = 0.
3. Plot the points (-2, 0), (-1, -3), (0, -4), (1, -3), and (2, 0). The graph is a parabola opening upward.

Tips and common mistakes

• Make sure you enter x as the variable, not y, because the calculator expects a function of x.
• If the graph looks strange, check parentheses carefully, especially in expressions like y = (x - 2)^2.

Frequently asked questions