Added first version of integrate.c. At the moment it works fine and is well commented, but only uses the sin() function from math.h, rather than dealing with passing function pointers.
Added first version of integrate.c. At the moment it works fine and is well commented,
but only uses the sin() function from math.h, rather than dealing with passing function pointers.

robintw/SESG6028Coursework1,robintw/SESG6028Coursework1