How do I write a recursive function to compute (3^2)+(3^3)+(3^4).......+(3^n) ?
How do I write a recursive function to compute (3^2)+(3^3)+(3^4).......+(3^n) ?
What have you done, besides posting your homework assignment?Show your code to us and pinpoint the errors you have.We will be more than happy to help. :)
Well said ddanbe.
Here the principle of recursive function :
Technically, a recursive function is a function that makes a call to itself. To prevent infinite recursion, you need to know the stop condition.
Here in your case the stop condition should be n == 1. and you should care about the specif case of n == 0.
An other hint?
What could the function prototype look like?
int sumToN( const int nSum, const int nTerm, const int N );
What would the tail recursive call look like?
How would you call the the function?
(What initial values ?)
not sure but is it something along the line of this?
int func(int base, int power)
{ base=3
if(power == 2)
return pow(base, power);
return pow(base, power) + function(base, power - 1);
}
Don't get why its saying I have too many arguments:
#include <iostream>
using namespace std;
//Function prototype
int function(int);
int main()
{
int number;
cout << "Enter an integer value and I will display\n";
cout << "the value: ";
cin >> number;
cout << "The function of " << number << "is";
cout << function(number) << endl;
system("pause");
return 0;
}
int func(int base, int power)
{ base=3;
if(power == 2)
return pow(base, power);
return pow(base, power) + function(base, power - 1);
}
Don't call your function, "function" or "func". Name it after what your function does.
You have defined a function prototype which can accept one int parameter, yet you use that function function with two parameters on line 25.
I'm getting error that says, LNK 1561: entry point must be defined error.
How do I fix this, am I doing this right?
#include <iostream>
#include <iomanip>
#include <cmath>
using namespace std;
//Function prototype
int func(int);
int main()
{
int number;
cout << "Enter an integer value and I will display\n";
cout << "the value: ";
cin >> number;
cout << "The function of " << number << "is";
cout << func(number) << endl;
system("pause");
return 0;
}
int func(int base, int power)
{ base=3;
if(power <= 2)
return pow(base, power);
else if (power==3)
return 27;
else
return pow(base, power) + func(base, power + 1);
}
Does line 7:int func(int);
look the same as line 22:int func(int base, int power)
?
If you can use an 'helper' calling function then ... HINT:
double sumToN( const double nSum, const double x, const double nTerm, const int N )
{
// if( N ...... /// return nSum;
// return sumToN( nSum + /////////////////////
}
// helper calling function ...
double sumToN( const double x, const int N )
{
return sumToN( 0, x, x*x, N );
}
Just fill in the 2 lines and you are done.