Evaluates the definite integral using Simpson's 3/8th Method.
integral = simpson2(a,b,n,f)
lower limit of integration
upper limit of integration
a multiple of 3 (denotes the no. of sub-intervals. Higher the value of n better the result.)
The function that is to be integrated
Returns the definite integral of a function using Simpson's 3/8th Method.
http://mathfaculty.fullerton.edu/mathews/n2003/Simpson38RuleMod.html