i need help writing a program that includes a function that computes future investment value at the given interest rate for a specified number of years. I have started out but do not know what to do next to get this program to work. here wut i have

#include <iostream>
#include <iomanip>
using namespace std;


double futureInvestmentValue(double investmentAmt, double monthlyInterestRate, int years);
int main()
{

double monthlyInterestRate, double investmentAmt;

cout<<"Please enter the investment amount: "<<endl;
cin>>investmentAmt;
cout<<"Please enter the interest rate: "<<endl;
cin>>monthlyInterestRate;
cout<<endl;


system("PAUSE");
return 0;

}

double futureInvestmentValue(double investmentAmt, double monthlyInterestRate, int years)
{
double investmentAmtValue;
int i, array[i];


accumulatedValue= investmentAmount*(1 + monthlyInterestRate) * (years *12)

for (i=0; i > 30;++)
{
array[i]=AccumalatedValue
cout<<array[i]<<endl;
{