Solving Integrals with Matlab

Hi everyone, i am working on a calculus problem that requires me to use Lobatto Quadrature and Global Adaptive Quadrature but i keep getting an error. Could someone explain how to write a code for this? Thanks.

Problem: f(x)=integral sign(3x^2)dx. Upper bound is 8 and lower bound is 0 on the integral sign.

% Lobatto Quadrature
A3= quadl(@(3*x,x(1),x(end))
% Global adaptive quadrature
intfun=@(x) (3*x.^2)
A4=integral(Intfun,x(1),x(end))

Answer 1

[Star Strider]

There is an error in the anonymous function in ‘A3’, and since MATLAB is case-sensitive, ‘Intfun’ is not the same as ‘intfun’. Also note that the functions for ‘A3’ and ‘A4’ are different.

This runs:

% Lobatto Quadrature
A3= quadl(@(x)3*x,x(1),x(end))
% Global adaptive quadrature
intfun=@(x) (3*x.^2)
A4=integral(intfun,x(1),x(end))

(I provided my own ‘x’ vector to test it.)