4.6 Trapezoid Rule



Many applications of calculus involve definite integrals. If it is possible to find an antiderivative for the integrand, then the integral can be evaluated using the Fundamental Theorem. When an antiderivative is not apparent, numerical (approximate) methods are invoked. The numerical method that is discussed in this section is called the Trapezoid Rule.

By the end of your studying, you should know:

On-screen applet instructions: The applet illustrates the Trapezoid Rule. Select the number of subintervals from the pull-down menu. For comparison, you can click the buttons at the bottom to see other approximations.



with 4 trapezoids. Sketch a figure showing the curve and the trapezoids involved. Compare your answer with the answer you find using integration formulas.

Compare the 5-subinterval trapezoid approximation of

with the exact value of the integral. How great is the difference between them?

How accurate is the Trapezoid Rule for approximating integrals?


Numerical Integration


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4.5 Techniques of Integration Table of Contents 4.7 Areas Between Curves

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Copyright © 2005 Donald L. Kreider, C. Dwight Lahr, Susan J. Diesel