f(x) = ln(x) in C++

[bolsey84]

alright, anybody know how to declare and write the following function in C++?

f(x) = ln(x)-5+x

Here is what I have tried

double rootFunction (double x, int 5)
{
double root;
root = ln(x)-5+x;
return root;
}

Any Ideas???? thanks

[saleem]

Why is 5 a variable? i dont think it should be, tho i may be wrong, i havent coded in years

double rootFunction (double x)
{
double root;
root = ln(x) - 5 + x;
return root;
}