Simpson's Rule Calculator

Approximate definite integrals using Simpson's numerical integration rules.

Function

Integration Bounds

Intervals (n)

Step size h = 0.250000

Evaluation Points

xf(x)Coef
0.00000.0000001
0.25000.0625004
0.50000.2500002
0.75000.5625004
1.00001.0000001

Integral of x^2 from 0 to 1

0.33333333

Simpson's 1/3 Rule

Simpson's 3/8
0.33333333
Step Size (h)
0.250000

Error Analysis

Exact Value0.33333333
Absolute Error0.0000e+0
Relative Error0.000000%

Simpson's 1/3 Rule Formula

Integral = (h/3)[f(x0) + 4f(x1) + 2f(x2) + 4f(x3) + ... + f(xn)]

Error: O(h^4) - Very accurate for smooth functions

About Simpson's Rule

  • Approximates f(x) with parabolic segments
  • Requires even number of intervals
  • More accurate than trapezoidal rule
  • Exact for polynomials up to degree 3