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Simpson's Rule Calculator

Approximate a definite integral with Simpson's rule (parabolic strips) — get the value, the step size, the estimated error, and a graph.

(h/3)[ f₀ + 4f₁ + 2f₂ + … + 4fₙ₋₁ + fₙ ]
∫ f(x) dx ,  a = a b = b n = n (even)

Simpson's rule approximates a definite integral using parabolas. n (the number of subintervals) must be even.

Results

Simpson's rule estimate
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Estimate
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h = (b − a)/n
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Subintervals n
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Approx. exact integral
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Approximation error
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Graph

f(x)area

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