about sqrt

#1
Guest_fxg03_*

Posted 16 July 2006 - 08:38 AM

Guests

Hi,
I am a beginner for C. I tried to make a simple program to use sqrt function to calculate square root. But I got some trouble.

Here is the simple program calculate.c:


#include <math.h>

#include <stdio.h>

#include <stdlib.h>

 main()

{ int i= 10;

   double j;

   j= sqrt (i);

}

Then I did the following:
cc calculate.c
And I got the error message:

/tmp/cc5EiCqg.o(.text+0x2a8d): In function 'main':
:undefined reference to 'sqrt'
collect2: ld returned 1 exit status

The system I used is Linux, and I don't know why this happens.
anybody can help me?

#2
Lop

Posted 16 July 2006 - 09:03 AM

Speaks fluent binary

Members
1,172 posts

I can't see any of your includes because you didn't put it in a code segment but it as long as you have math.h included it should work. You just need to link to the math library

"cc calculate.c -lm"

Just tried it and it works perfectly.

#3
Guest_fxg03_*

Posted 16 July 2006 - 10:57 AM

Guests

Thanks Lop.
It works now.

#4
Guest_Jordan_*

Posted 16 July 2006 - 11:51 AM

Guests

Added code tags around the block of code. The < and > arn't working for some reason.

<string.h>

#5
John

Posted 20 July 2006 - 01:59 PM

Writes binary right handed and hex left handed

Moderators
6,321 posts

i thought if you include header files or something you go like

#include "stdafx.h"

but if u include a library you use the < and >

#include <iostream>

#6
Lop

Posted 21 July 2006 - 05:10 AM

Speaks fluent binary

Members
1,172 posts

Good question sidewinder...... I'm pretty sure either way will work for either. That is odd though, I've never really noticed that until you pointed it out. Maybe someone else can shed some light on this.