Integral Calculator with Steps

Find a verified symbolic antiderivative or evaluate a finite definite integral. The calculator shows the integration rules used, applies adaptive numerical integration when needed, and graphs the integrand with signed area—all locally in your browser.

Enter an integrand

Use ^ for powers. Functions include sin, cos, tan, sec, csc, cot, asin, acos, atan, sinh, cosh, tanh, sech, exp, ln, log, sqrt, and abs.

Try an example

Keyboard shortcut: Ctrl/ + Enter.

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Integral

Entered integral
Enter an integrand to begin.
Antiderivative
The result will appear here.

Step-by-step integration

Integration steps will appear here.

Integrand and signed-area graph

Integrate a function to draw its curve. Definite mode shades the interval between the curve and horizontal axis.

Calculator methodology and review

Developed and reviewed by
Starlight Robotics calculator team
Last reviewed
Symbolic method
Parse expression tree → match verified integration rules → simplify → differentiate the candidate antiderivative for a numerical identity check.
Numerical method
Adaptive Simpson quadrature over finite bounds with interval scanning and an error estimate.
Input limits
One selected variable, 300 characters, finite definite bounds and real-valued continuous numerical intervals.
Privacy
The function and results remain in your browser; the calculator does not call a solving API.

How to use the integral calculator

  1. Choose Indefinite for an antiderivative or Definite for a value between finite bounds.
  2. Enter a function such as 4x^3-5x+7, 2x*cos(x^2), or exp(-x^2).
  3. Select the variable and, for definite mode, enter lower and upper bounds.
  4. Select Integrate to see the result, method, steps, verification and graph.

Multiplication may be explicit or implicit. Function names require parentheses, and trigonometric inputs use radians.

Symbolic and numerical integration

Symbolic antiderivatives

Polynomials, linear powers, reciprocal-linear forms, common trig and hyperbolic functions, exponentials, logarithms, inverse-trig primitives, recognizable u-substitution patterns, and polynomial products handled by repeated integration by parts produce verified formulas.

Adaptive numerical fallback

A continuous definite integral can still be evaluated when the engine has no implemented elementary primitive. Refined Simpson estimates continue until the selected tolerance is met.

Fundamental Theorem

When an antiderivative F is available, the definite integral is evaluated as F(b)−F(a) and cross-checked numerically.

Signed area

Area above the horizontal axis contributes positively and area below it contributes negatively. The graph uses separate shading for both.

Worked integral examples

Polynomial power rule

∫(4x³−5x+7)dx

Increase each exponent and divide: x⁴−(5/2)x²+7x+C.

u-substitution

∫2x cos(x²)dx

Let u=x², so du=2x dx. The result is sin(x²)+C.

Definite sine integral

∫₀^π sin(x)dx

An antiderivative is −cos(x), so −cos(π)−[−cos(0)]=2.

Numerical fallback

∫₀¹ exp(−x²)dx

This non-elementary antiderivative is evaluated numerically as approximately 0.7468241328.

Integral calculator FAQs

What is the difference between an indefinite and definite integral?

An indefinite integral returns a family of antiderivatives with + C. A definite integral returns accumulated signed area between two bounds.

What happens when there is no elementary symbolic answer?

Indefinite mode reports that no supported elementary form was found. With finite bounds, definite mode uses adaptive Simpson integration and labels the answer numerical.

How does the calculator verify symbolic results?

It differentiates the candidate antiderivative and compares the result with the original integrand at representative valid points.

Why was a definite integral rejected?

The function may be undefined, non-real or apparently singular inside the interval. Split the interval only when the corresponding improper integrals are mathematically valid.

Does the result represent geometric area?

It represents signed area. Portions below the axis subtract from portions above it.

Are trigonometric inputs in radians?

Yes. Standard calculus integration rules assume radian measure.

Does my expression leave the browser?

No. Symbolic matching, differentiation checks, quadrature and graphing run locally on your device.

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