how to find the numerical integration in matlab
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Input: syms a b phi h=int((sin(phi)/(sqrt(a+(b*sin(phi))))),phi) h1=vpa(h)
Ans: Warning: Explicit integral could not be found.
h =
int(sin(phi)/(a + b*sin(phi))^(1/2), phi)
h1 =
numeric::int(sin(phi)/(a + b*sin(phi))^(1/2), phi)
Help me to find out the mistake and tel me how to find out the numerical integration.
2 Comments
Roger Stafford
on 3 Feb 2014
Your integral can be expressed in terms of a combination of elliptic integrals of the first and second kinds. Perhaps it would help in obtaining a symbolic expression to this effect if you declared symbols for its upper and lower limits of integration.
As Wayne has pointed out, with or without such a symbolic expression, to obtain a numerical value for the integral you will need to give specific numerical values to both these limits and to the coefficients a and b.
Answers (2)
Wayne King
on 3 Feb 2014
Edited: Wayne King
on 3 Feb 2014
What version of MATLAB are you using? There is an integral() function for numerical integration.
Of course, you'll need values for a and b and limits of integration
a = 1;
b = 2;
f = @(x) sin(x)./sqrt(a+b*sin(x));
integral(f,0,2);
Wayne King
on 3 Feb 2014
a = 1;
b = 2;
f = @(x) sin(x)./sqrt(a+b*sin(x));
quad(f,0,2);
3 Comments
Wayne King
on 4 Feb 2014
yes, if you are changing the limits of integration, you get a different value for the definite integral.
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