C++ Program (using a function) to accept a number and print its Cube

#include<iostream.h>
#include<conio.h>
float cube(float);  //function cube's declaration
int main()
{
clrscr();
float num;
cout<<"\n\t Enter a Number:";
cin>>num;
cout<<"\n"<<"The Cube of"<<num<<"is"<<cube(num)<<"\n";
return 0;
}
float cube(float a)  \\function cube's definition
{
return a*a*a;
}