6. Numerical Integration 6.1 Definition of numerical integration. 6.2 Reasons to use numerical integration. 6.3 Formulas of numerical Integration. 6.4 Applications of numerical integration.
6.1 Numerical Integration
Degree of Precision
6.2 Reasons to use numerical integration Form of the function is not known. Integrand is not known clearly. Integrand is known but it is difficult or impossible to find antiderivative.
6.3 Quadrature formula
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Trapezoidal Rule
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Simpson’s 1/3 rd Rule
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Simpson’s 3/8 th Rule
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Example A solid of revolution is formed by rotating about the x-axis, the lines x = 0 and x = 1.5, and a curve through the points with the following coordinates Estimate the volume of the solid formed, giving the answer to four decimal places by Trapezoidal rule, Simpson’s ⅓ and Simpson’s ⅜ rule of integration. x y
Solution X
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Error Then the absolute relative approximate error obtained between the results from Trapezoidal rule and Simpson’s ⅓ rule is and the absolute relative approximate error obtained between the results from Simpson’s ⅓ rule and Simpson’s ⅜ rule is
Comparison table Table:-Comparison of results of different methods of numerical Integration. Method of Integration Trapezoidal ruleSimpson’s ⅓ ruleSimpson’s ⅜ rule Volume Absolute relative Approximate error
Applications of numerical integration. Numerical integration is specially used in statistics in maximum likelihood & normal distribution. It is also used in cloud computing and to find out the definite integral when we are not knowing the form of the function etc.