How do I type a define integral?

Hello, I seem to have a problem in Matlab when I try to run a certain function, and this always appears "First input argument must be a function handle." Here's my code:

     f= pi*(10^2 - 5^2);
     F = integral(f,-3.53553390,3.535533906);

Im trying to calcute the volume of a toroid using this integral, 'f' was supossed to be: pi(Re^2(y) - Ri^2(y))dy. The limits been '-r' and 'r'. And to verify the volume i have V=2*pi*R*r^2.

Now.. I've been doing a little research and I think i have to use something like'@(x)' before the function. Please help.

Answer 1

[Star Strider]

See if this does what you want:

f = @(y) pi*(y.*10^2 - y.*5^2);                             % Create Anonymous Function, Add ‘y’
F = integral(f,-3.53553390,3.535533906);                    % Integrate

See the documentation on Function Basics, particularly the section on Anonymous Functions.