solve some integrals using trapezoidal rule and a matlab built-in function and to represent the original function in a graph

It is asked to solve some integrals using trapezoidal rule and a matlab built-in function and to represent the original function in a graph.

Here is the code i did:

    f1=@(x) (x.^2+1)/((x+2).*sqrt(1-2*x));
    a=0; b=.5;
    N=100;
    figure()
    fplot(f1,[a,b])
    grid on
    res_trap=trapezios(f1,a,b,N);
    res_matlab=integral(f1,a,b);
    f1=@(x)((sin(x))/x.^2);
    figure()
    fplot(f1,[0,10])
    grid on
    a=1; b=inf;
    N=10;
    res_trap=trapezios(f1,a,b,N);
    res_matlab=int(f1,1,inf);
    syms t
    f1=@(x,y)x.^2*y;
    a=0; b=y; c=0; d=1;
    eixox=@(y)y;
    ezsurf(f1,0,eixox(),0,1)
    res_trap=trapezios(f2,c,d,N);
    res_matlab=int2(f1,0,1,0);

Here is the trapezoidal integration function I did:

function It=trapezios(f,a,b,N)
h=(b-a)/N;
It=0;
for k=1:(N-1)
     x=a+h*k;
     It=It+feval(f,x);
  end
It=h*(f(a)+f(b))/2+h*It;
end

When i run the code several errors occur. What is wrong?

[Image Analyst]

You might get answers faster if you told people what the errors were rather than forcing them to copy the code, switch to MATLAB, paste the code, and then run it.

Answer 1

[Walter Roberson]

Vectorize your division, not just your multiplication.

f1=@(x) (x.^2+1)./((x+2).*sqrt(1-2*x));