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Integral Calculator

Free Integral Calculator for calculus. Enter values to get step-by-step solutions with formulas and graphs. See charts, tables, and visual results.

Reviewed by Manoj Kumar, Mathematics Educator

Reviewed by Manoj Kumar, Mathematics Educator

Formula

Simpson's Rule: โˆซf(x)dx โ‰ˆ (h/3)[f(xโ‚€) + 4f(xโ‚) + 2f(xโ‚‚) + 4f(xโ‚ƒ) + ... + f(xโ‚™)]

Simpson's 1/3 rule uses quadratic interpolation for numerical integration. It requires an even number of subintervals. Error is O(hโด), making it much more accurate than the trapezoidal rule for smooth functions.

Worked Examples

Example 1: โˆซxยฒ from 0 to 1

Problem:f(x) = xยฒ, bounds [0, 1]

Solution:โˆซxยฒdx = xยณ/3 |โ‚€ยน = 1/3 = 0.33333333

Result:0.33333333

Example 2: โˆซsin(x) from 0 to ฯ€

Problem:f(x) = Math.sin(x), bounds [0, 3.14159265]

Solution:โˆซsin(x)dx = [-cos(x)] from 0 to ฯ€ = (-cos(ฯ€)) - (-cos(0)) = 1 - (-1) = 2

Result:โ‰ˆ 2.00000000

References

Reviewed by Manoj Kumar, Mathematics Educator ยท Editorial policy