Pow and Math.h

[ultrabot90]

Made console project.
I tried to used pow() function.
Didnt work.
Nor did any math.h function.
In fact, it does not detect any math.h file.
What should I do?
-regards,
ultrabot90

[killerbot]

1) C++ project ?
2) assuming yes on 1)

in your cpp file :
#include <cmath>

using namespace std;

[TDragon]

Please post a small example of the code that doesn't work, and the contents of the Build log tab in the Messages area, after a failed build.

[ultrabot90]

*smashes head*
Sorry for being so damn unspecific. -_-'
Its C++.
Cmath worked, thanks.
And now same program, new problems.

Code Select Expand

#include<iostream>
#include<cmath>
using namespace std;
void series(int, int);
int main()
{
    int x, n;
    cout<<"\nEnter the value of x & n…\n";
    cin>>x>>n;
    series(x, n);
    return 0;
}
void series(int x, int n)
{
    int sum=1,f=1,j;
    for(int i=1;i<=n;i++)
    {
        for(int j=1;j<=(2*n-1);j--)
        f*=j;
        sum+=f/pow(x,i); //Line 20
    }
    cout<<"\n"<<sum;
}
Line 20 - Error - Call of overloaded function 'pow(int&, int&)' is ambigous
Help please.

[darkwalk]

http://cppreference.com/stdmath/pow.html

from the reference, pow takes arguments:   double base, double exp

Instead, your function is invoked using something else.  Cast your second argument into a double, adn you should be good.

[ultrabot90]

thx! ^_^

[killerbot]

and important !!!

Your code is actually not correct. You have to specify to use the std namespace (always do this in cpp files, never headers).

You can :

a) using namespace std;

or specify just what you need :
b)
using std::cout;
using std::cin;
using std::pow;

[ultrabot90]

I think I did type in the "using namespace std;" line...
Another problem is that C::B always returns a "Warning : No newline at end of file."
Its there in any program I do. Even the previous one.
Thats the entire lot of problems, I think.

[killerbot]

it's no CB that's bugging you, it's the compiler.
A lot of compilers want all files to end with an empty line.

Just make a (good) habit out of it ;-)

[ultrabot90]

oO
Ok...That did the trick.
Thanks.

[transfrank]

Hello,
I did

Code Select Expand

#include <cmath>
using name space std;

and upon compilation, code::blocks opens up the cmath file and gives the following error message for all the math functions, (e.g. like for arc cosine):

Code Select Expand

error '::acos' has not been declared

Also, I added under Project build options-> linker settings->link libraries : m for math.
Advice on what us wrong?
Thanks,
Frank

[stahta01]

Code Select Expand

#include <cmath>
using name space std;

It is namespace not name space!

Tim S

[transfrank]

I did namespace in the code and just typed it too quickly here. So my problem persists.