Calculating APY formula in C

Question

Im trying to calculate an APY formula and when compiled it shoots out 0.0000 when there is an input. I don't know if there is an error in my code or in the way im compiled it, but the answer should be output to .0618 when .06 in input.

    /* "APY.c", APY Calculator

Name: Tanner Oelke

Date: 2015/09/01

*/



#include <stdio.h>

#include <stdlib.h>

#include <math.h>



int main(void) {

    //define variables

    double apy, nominalIntRate;



    //ask user for interest rate

    printf("Please enter nominal interest rate:");

    scanf("%lf", &nominalIntRate);



    //calculates apy

    apy = exp(nominalIntRate) -1;



    printf("The APY is: %.4lf\n", &nominalIntRate);



    return 0;



}

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Answer 1

You have a good framework but there are two flaws in your program. First of all, scanf takes a pointer to the variables it reads into so as to be able to alter their values, but printf does not require a pointer, just the value. Secondly, you should print the value you want, not some other value. The line

printf("The APY is: %.4lf\n", &nominalIntRate);

should read

printf("The APY is: %.4lf\n", apy);

Calculating APY formula in C

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