Numerical Methods coding -- where am I wrong??

I gotta essentially create code on MATLAB for the Trapezium rule, and Simpson's 1/3 rule. I have done this. Then I gotta test these on a certain function $f$ between two bounds and plot the errors for using both methods.

Now, I'm pretty sure I'm going wrong somewhere since my trapezium errors are smaller than simpson's errors! Simspson's is supposed to be more accurate so I think I'm going wrong somewhere but I dunno where??

Can someone check my code for me? Thx!

https://imgur.com/a/r6Y5BPd

Don't know Matlab, but looking at the Simpson's rule code, it looks as if sum2 contains terms f(2)+f(4)+...+f(n); shouldn't this be only f(2)+f(4)+...+f(n-2)?

Aw crap you're right!! Thanks!

It looks much better now