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Taylor Series Function

Posted on 16th Feb 2014 07:03 pm by admin

So I am working a a project for my intro C++ class, and I am having some trouble with a function for approximating exp(x) using a taylor series. The taylor series approximations for exp(x) is: 1+x+((x^2)/2!)+((x^3)/3!+...., and I am supposed to approximate to "n" number of terms.

Thus far, my function is this:

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double fact(int c) { int factorial=1; for ( int i = 1; i <= c; i++ ) { factorial *=i; } return factorial; } double taylor(double x, int n) { double approx; double sum; double value; for (int i=1; i<=n; i++) { int factorial=1; factorial*=i; sum=((pow(x,i))/fact(i)); value+=sum; } approx = 1+value; return approx;

Now this does work if I just run it by itself, i.e. just do something like "cout << taylor(x,n)". But whenever I call this function within another function, it does not work! It is kinda hard to explain, but anyone have any ideas?

Thanks

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