Trapezoidal Rule Calculator
Approximate the definite integral of a function using the trapezoidal rule. Enter the function, limits, and number of subintervals to get an approximation.
Published by:
isCalculator Editorial Team
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How to Use the Trapezoidal Rule Calculator
This calculator approximates the definite integral of a function f(x) from a to b using the trapezoidal rule.
- Enter the function in the f(x) field. Use
xas the variable. Supported operators:+,-,*,/,^(power),sin,cos,tan,log,sqrt,pi,e. Example:x^2. - Set the lower limit a and upper limit b. Ensure a is less than b.
- Choose the number of subintervals n (must be at least 1). Larger n gives a more accurate result.
- Click Calculate Integral. The result appears as an approximation with 6 decimal places.
- Below the result, you'll see the formula used and the step size h.
Note: All numeric inputs accept decimals. Use standard mathematical notation (e.g., sin(x) for sine).
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Frequently Asked Questions
The trapezoidal rule is a numerical integration method that approximates the definite integral of a function by dividing the area under the curve into trapezoids and summing their areas.
Use x as the variable. Supported operators: +, -, *, /, ^ for power, and functions like sin, cos, tan, log, sqrt, pi, e. Example: x^2 + sin(x).
n is the number of subintervals (trapezoids). A larger n generally gives a more accurate approximation. Must be a positive integer.
