The document provides matlab code to approximate the integral I = ∫11 exp(-x^2)dx in three different ways: 1) Using the quad command with default settings to integrate over [-1,1]. 2) Using the trapezoidal rule over [-1,1]. 3) Using the composite trapezoidal rule over [-1,1] divided into 20 sub-intervals. The results of approximations 1 and 3 are saved to files A01.dat and A03.dat respectively.

1. Please provide the matlab code for this question. Thank you.
Consider the integral I =^1_1 exp(-x^2)dx Approximate the integral I with theMATLAB
command quadover [-1,1] and default settings otherwise. TASK:Save the resulting
approximation Iquadin the file A01.dat Approximate the integral I with the trapezoidal rule over
[-1,1] (recall that the trapezoidal rule uses only the values at -1 and 1) Approximate the integral I
with the composite trapezoidal rule and the interval [-1,1] into m = 20 sub-intervals of same
length. TASK: Save the resulting approximation Idrapin the file A03.dat.
Solution
1)))))))))
fun1 = @(x) exp(-x.^2);
A01 = integral(fun1,-1,1);
2))))))))))))
x=-1:1;
y = exp(-x.^2);
A02 = trapz(x,y);
3)))))))))))))
function integral = cmptrap(a,b,n,f)
h = (b-a)/n;
x = [a+h:h:b-h];
integral = h/2*(2*sum(feval(f,x))+feval(f,a)+feval(f,b));
%Run with
cmptrap(-1,1,20,f)
%where ’f’ is the name of the function definition file
function y = f(x)
y = exp(-x.^2);