How could I check my solution if I am doing a definite integration please?? I mean,since a definite integral is the limit of a sum so could I write a code using sum to check my results??

1 view (last 30 days)
Avan Al-Saffar
Avan Al-Saffar on 27 Oct 2014
Answered: Torsten on 27 Oct 2014
integral(f(x),a,b)=sum(f(xi),1,N)?

Answers (2)

Mischa Kim
Mischa Kim on 27 Oct 2014
Avan, yes you could. For example:
f = @(x) sin(x);
a = 1;
b = 5;
N = 100;
f_int1 = integral(f,a,b)
f_int2 = sum(arrayfun(f,linspace(a,b,N)))*abs(b-a)/N
Try increasing N. Note that you need to sum up small rectangular areas of size f(x)*dx.

Torsten
Torsten on 27 Oct 2014
I guess your question aims at the integration of the expression
f = @(T) ( A*(((N0*sin(omega*T).^2.*(1-2*P(T)./k))+(omega.*cos(omega*T) ) ).^2)./(N0.^2*sin (omega*T).^4.*(P(T)-P(T).^2./k).^2) )
from the other thread you opened.
Did you notice that the denominator of your above expression is zero at T=Pi and f thus becomes infinity at this point ?
Best wishes
Torsten.

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!