Integral Calculator
Definite and indefinite integrals computed symbolically via the power rule, linear substitution, and standard antiderivative tables. Supports polynomial, trigonometric, exponential, and logarithmic functions. Falls back to adaptive Simpson quadrature when no closed-form antiderivative exists, with configurable precision from 2 to 10 decimal places.
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Documentation
The integral calculator computes definite and indefinite integrals of a function symbolically, applying the power rule, linear substitution, and standard antiderivative tables across polynomial, trigonometric, exponential, and logarithmic functions. An indefinite integral yields the antiderivative as a function; a definite integral evaluates that antiderivative between a lower bound and an upper bound to produce a single numeric value.
- Function notation follows standard convention:
x^2for powers,sin(x)for trigonometric functions,e^xorexp(x)for exponentials,ln(x)orlog(x)for natural logarithms,sqrt(x)for square roots, and*for multiplication. - Integration can be carried out with respect to any single variable, not only
x, such ast,u, ortheta. - Bounds for a definite integral accept decimals, fractions (such as
3/4), mixed numbers (such as1 1/2), and scientific notation (such as1.5e3). - Decimal precision is adjustable from 2 to 10 places, and a step-by-step solution can be shown to display each stage of the integration.
- Supported function forms include polynomial terms (
ax^n), trigonometric functions (sin, cos, tan, sec, csc, cot), inverse trigonometric functions, exponential functions (e^x,a^x), logarithmic functions (ln(x)), square roots (sqrt(x)), and constant multipliers. - When a function has no closed-form antiderivative, the calculator falls back to adaptive Simpson quadrature, a numerical method that approximates the definite integral to the selected precision.
Integrating f(x) = x^2 by the power rule gives the antiderivative x^3/3. As a definite integral from 0 to 2, that is (2^3)/3 - (0^3)/3 = 8/3 - 0 = 8/3, or approximately 2.6667 at four decimal places.
Integration is fundamental across mathematics, science, engineering, and economics, and this calculator covers a broad spectrum of integration problems from academic study to professional practice.
- Calculus Students: Verify homework answers and exam preparation by checking indefinite integrals of polynomial, trigonometric, and exponential functions. Entering an expression like x^3 - 2*x + 5 gives an antiderivative to compare against manual work.
- Physics and Engineering: Compute definite integrals for problems involving displacement from velocity functions, work done by variable forces, or electric flux calculations. Evaluating an integral such as sin(x) from 0 to pi confirms analytical results.
- Statistics and Probability: Calculate areas under probability density functions and cumulative distribution values by evaluating definite integrals over specified intervals.
- Economics and Business: Determine consumer surplus, producer surplus, or total revenue by integrating demand and supply functions over relevant price or quantity ranges.
- Research and Publication: Verify integral computations that appear in research papers or technical reports, using the step-by-step output to confirm that intermediate results match expected derivations.
- Teaching and Tutoring: Generate worked examples for classroom demonstrations or tutoring sessions. The step-by-step feature lays out clear explanations that help students understand integration techniques and rules.
- Numerical Analysis: Evaluate definite integrals of complex functions with no closed-form antiderivative using the built-in adaptive numerical integration method, accurate to the selected precision level.
Inputs, outputs, and what the Integral Calculator computes
What the Integral Calculator asks for and what it returns, as a plain list. Defaults, units, and ranges are the ones the form loads with.
Inputs
- Indefinite Integral / Definite Integral · default: Indefinite Integral
- Function f(x) (text input)
- Variable of Integration (text input) · default: x
- Lower Bound (a) (text input) · default: 0
- Upper Bound (b) (text input) · default: 1
- Decimal Precision · default: 6
- Show step-by-step solution · default: off
Controls
Calculate · Reset
Example
Integrating f(x) = x^2 by the power rule gives the antiderivative x^3/3 .