A definite integral had a minimum and maximum limit. When you solve this type of problem you must use both quad and the trapz functions (easy), returning the absolute value of their difference which should be zero.
Bruce, please check the answers to your test suite. Granted, it has been a while since I took calculus in college, but I'm pretty sure the answers aren't all zero. :-)
Never mind...just noticed you were looking for the error differences, and not the actual values. It's been a while since I took a Reading Comprehension class as well...
This is an "honor system" test suite. For the last case, quad('2*x',0,2) gives 3.9999999999999996, while trapz([0:1/n:2],[0:2/n:4]) gives the exact answer 4 for all values of n from 1 to 100, except n=35, 44, 51, 69, 92, or 100, which all give the same answer as quad.
558 Solvers
Solve the set of simultaneous linear equations
160 Solvers
232 Solvers
I've got the power! (Inspired by Project Euler problem 29)
62 Solvers
352 Solvers