1. ## Question..

How do I use the pow command?

I need to basicly do 10^x

I dont know how to do it with the pow command if any one could help me I would be thankful

2. <batman>
pow!!!!
zap!!!!
</batman>

> How do I use the pow command?
n = pow(x, y);

3. >How do I use the pow command?
Code:
`double answer = pow(10., x)`

4. Code:
`double pow( double base, double exp );`
As such,

Code:
```double result;
double exp = 3; // for instance

result = pow(10.0, exp);```
Do NOT use integers with this function. The standard states that implementations are free to overload floating-point functions to their float, double and long double types. So, its possible that your implementation has pow defined as:

double pow( float base, float exp );
double pow( double base, double exp );
double pow( long double base, long double exp );

If you use an integer as an argument to one or both parameters, the compiler will complain your attempt is ambiguous. Even if it does not (because some compilers do not overload or provide preprocessor policies), your code may fail to compile on other implementations.

5. >Do NOT use integers with this function.
Doesn't C++ have a:
Code:
`double pow( double base, int exp );`
I have no idea how to check this. Maybe the C++ standard has a list?

6. If you need to do ints, just write it all out:
Code:
`x = x*x*x*x*x*x*x*x*x*x      //x^10`

7. Originally Posted by manutd
If you need to do ints, just write it all out:
Code:
`x = x*x*x*x*x*x*x*x*x*x      //x^10`
You are joking right?

8. Yes.

9. I checked the library for Dev-C++ and it does have a:
Code:
`double pow( double base, int exp );`
I dunno if it's standard though.

10. It's not. I don't understand why you can't just use a cast to double for intermediate use of pow() though.

11. As citizen said. It's not a big deal to use a cast in this situation. Cast to whatever floating-point type is more appropriate, adorn the literal or define floating-point variables, do what you must. But avoid using integers even if your compiler happily says everything is alright

12. >It's not.
Do you have a copy of the C++ standard to verify that? Because I'm fairly certain it's in there.

13. >But avoid using integers even if your compiler happily says everything is alright
I see no reason to avoid using int for the exponent. Unless you're compiling C code.

14. > Do you have a copy of the C++ standard to verify that?
I can find a reference.
http://www.dinkumware.com/manuals/?m...=math.html#pow
Barring you don't trust that, various implementations will let you know what is available by extention if you look it up in the help files.

15. Well... the standard does in fact state the following signatures for pow (26.5.6):

float pow(float, int)
float pow(float, float)
double pow(double, int)
double pow(double, double)
long double pow(long double, int)
long double pow(long double, long double)

So yes, an int exponent will not generate ambiguity.