How I plot approximate solution of a boundary value problem using my below code ?

I have tried to plot the approximate solution for boundary value problem using my below code such that I have tried ezplot command but dosn't work .approximate solution that I have got are : -1.33,-1.1660,-1.3320

**Code **

N=4;

n=N-1;

a=-1;b=1;h=(b-a)/N ;

x=linspace(a,b,N+1);

x=x(2:end-1);

A=diag(ones(n,1));

B=diag(ones(n-1,1),-1);

C=diag(ones(n-1,1),1);

K1=1/h*(2*A-B-C);

K2=h*(4*A+B+C)

K=K1+K2;

K(1,1)=K(2,2)/2;

K(n,n)=K(1,1);

f=@(x) (-4*x^2-6)*exp(x^2);

b=zeros(n,1);

for i=1:n

b(i)=h*f(x(i));

end

b(1)=h/2*f(x(1));

b(n)=h/2*f(x(n));

U=pinv(K)*b