Help with a couple compiler errors

Greetings,
I'm kind of new to the C language and I had to write a program that computes a monthly payment. I'm using the gcc compiler and when I run the compile, I get the following messages:

loan.c: In function "int main":
loan.c:34: error: too few arguments to function 'pow'

Any ideas? Here is my code:

Code:

     /*
         Filename: loan.c
         Description: The monthly payment for an installment loan.
     */


#include <stdio.h>
#include <math.h>

 int main()

  {

      /* memory allocation for data */

      double monthlypayment;
      double principal;
      double rate;
      int months;

      /* prompt user for data */

  printf ("Enter the principal amount of the loan:");
  scanf  ("%lf",& principal);

  printf ("Enter the yearly interest rate (eg.0.05):");
  scanf  ("%lf",& rate);

  printf ("Enter the total number of payments in months:");
  scanf  ("%d",& months);

       /* compute monthly payment */

       monthlypayment = principal*(rate/12)/1-pow(1+rate/12)-months;

       /* display result */

  printf ("Your monthly payment will be: $%lf/n",monthlypayment);

       /* End */

 return 0;

  }

What are you trying to do?

pow takes two arguments, for example pow(2,3) will compute 2 raised to the power of 3. You are only giving one argument.

Edit:

Also, remember that if you divide by an integer value, the result will be an integer. You probably want rate/12.0