Formula problem

[aballbest]

Forgive an old man. I am trying to help my son as he learns C++. It has been 30 years since I took my programming in college. Need to know how to write the formula
a= pr
-----------------
1_[1+r]-n



a is given loan amount, APR and length of loan.

p is a standard dollar figure
r is 1 twelvth of the APR
n is number of monthly payments which will be an integer greater than zero and could reach 60

here is what he and I have so far total = (principal * (1/12)*rate) / (1 - powf((1 + (1/12)*rate), -length));


any help is appreciated.

 

[babusats]

here is what he and I have so far total = (principal * (1/12)*rate) / (1 - powf((1 + (1/12)*rate), -length));

double x = rate/12.
x++;
double y = - length;
double denom = pow(x,y);
denom = 1 - denom;
double numer = princi /12. * rate;
double a = numer / denom;

This will work;
R.Sathish.
babusats@rediffmail.com