errors using Numerical Integration

I am trying to find the integral of the following function

y = @(x) 1/(sqrt(1+x.^4));  %function
a = -1; b = 1;  %limits
x = a:.01:b;
S_int = integral(y,a,b);    %integral function
S_trap = trapz(x,y);

fplot(y,[a,b])
xlabel('x'); ylabel('f(x)'); grid on
str1 = ['Integral of f(x) from ',num2str(a)];
str2 = [' to ',num2str(b),' is ',num2str(S)];
title([str1,str2]) 

fprintf('The integral to the function using the integral function is is %.6f\n', S_int);
fprintf('The integral to the function using the trapz function is is %.6f\n', S_trap);

function y = f(x)
y =  1/sqrt(1+x.^4);
end

I keep getting a myriad of errors that I'm not sure what to do about and would appreciate any help, Thank you!

Answer 1

[the cyclist]

I see three errors:

(1) You need elementwise division instead of matrix division:

y = @(x) 1./(sqrt(1+x.^4));  % note the added dot

(2) For trapz, you need the numerical evaluation of y:

S_trap = trapz(x,y(x)); % Note the argument to y()

(3) There is no variable S. I assume you want one of your S_int or S_trap values.

[Elle Rae]

Thank you!

Answer 2

[David Hill]

y = @(x) 1./(sqrt(1+x.^4)); %just need a dot (./)
a = -1; b = 1; 
S_int = integral(y,a,b);