Simpsons method for numeric integration

SIMPSON's method for numerical calculations and analysis exercises in Numeric Integration.

SIMPSON's method for numerical calculations and analysis exercises in Numeric Integration. f function is given in terms of a symbolic variable x and as an inline function. E.g., f=inline('x^2+2*x-2'). Also, if the function
f is trigonometric function, the 4th argument can be entered as 'trigonom' or just 'trig' or 1. X is expected to be in degrees for trigonometric function evaluations. upl and lowl are upper and lower limits. NB: A sequence order of limits is unnecessary to follow, 'if' conditions will take care of lower and upper limits accordingly.