My program performs operations on complex numbers, however, I'm confused on how my exponent function can take only one complex number and take it to a power. I keep on getting an errror.
header
MultC is a member function of a class, not a standalone function.
Did you mean
x = x.MultC( x, n);
on line 37 of what you have (mistakenly) called driver?
Also, the way you have set it up is very odd. Surely you would want to write
c=a.ExpC(n);
and not what you have on line 32 of what you (mistakenly) call implementation? Object a is effectively redundant there.
C++ has a complex number class and function templates for manipulating complex numbers in the <complex> header, including a function for raising to power: std::pow().