Programming Forums > Application Development > C

Benoit · Oct 15th, 2004, 10:32 PM

I made a program to find the nth root of a number, but when I try to compile gcc gives me this error:

/tmp/ccFcU3yg.o(.text+0x5e): In function `main':
: undefined reference to `pow'
collect2: ld returned 1 exit status

(Toggle Plain Text)

#include<stdio.h>
#include<math.h>

main()
{
float num,nth,root;

printf("num: ");
scanf("%f",&num);
printf("\nnth: ");
scanf("%f",&nth);

root=pow(num,(1/nth));
printf("\nThe %f root of %f is %f\n",nth,num,root);
}

Mjordan2nd · Oct 15th, 2004, 11:16 PM

Add -lm at the end of your compile line.

(Toggle Plain Text)

 gcc -o pow pow.c -lm

Benoit · Oct 15th, 2004, 11:18 PM

Thanks dude

What does -lm do?

Mjordan2nd · Oct 15th, 2004, 11:21 PM

It links to libm, I believe.

Oct 15th, 2004, 10:32 PM	#1
Benoit Expert Programmer Join Date: Sep 2004 Location: Ontario, Canada Posts: 574 Rep Power: 5	I made a program to find the nth root of a number, but when I try to compile gcc gives me this error: /tmp/ccFcU3yg.o(.text+0x5e): In function `main': : undefined reference to `pow' collect2: ld returned 1 exit status (Toggle Plain Text) #include<stdio.h> #include<math.h> main() { float num,nth,root; printf("num: "); scanf("%f",&num); printf("\nnth: "); scanf("%f",&nth); root=pow(num,(1/nth)); printf("\nThe %f root of %f is %f\n",nth,num,root); } #include<stdio.h> #include<math.h> main() { float num,nth,root; printf("num: "); scanf("%f",&num); printf("\nnth: "); scanf("%f",&nth); root=pow(num,(1/nth)); printf("\nThe %f root of %f is %f\n",nth,num,root); } __________________ Johnny was a chemist's son but Johnny is no more, for what Johnny thought was H2O was H2SO4

Oct 15th, 2004, 11:16 PM	#2
Mjordan2nd The Supreme Ruler Join Date: May 2004 Location: Houston Posts: 1,476 Rep Power: 6	Add -lm at the end of your compile line. (Toggle Plain Text) gcc -o pow pow.c -lm gcc -o pow pow.c -lm __________________ "Every gun that is made, every warship launched, every rocket signifies, in the final sense, a theft from those who hunger and are not fed, from those who are cold and are not clothed. The world in arms is not spending money alone. It is spending the sweat of its laborers, the genius of its scientists, the hopes of its children." - Dwight D. Eisenhower

Oct 15th, 2004, 11:18 PM	#3
Benoit Expert Programmer Join Date: Sep 2004 Location: Ontario, Canada Posts: 574 Rep Power: 5	Thanks dude What does -lm do? __________________ Johnny was a chemist's son but Johnny is no more, for what Johnny thought was H2O was H2SO4

Oct 15th, 2004, 11:21 PM	#4
Mjordan2nd The Supreme Ruler Join Date: May 2004 Location: Houston Posts: 1,476 Rep Power: 6	It links to libm, I believe. __________________ "Every gun that is made, every warship launched, every rocket signifies, in the final sense, a theft from those who hunger and are not fed, from those who are cold and are not clothed. The world in arms is not spending money alone. It is spending the sweat of its laborers, the genius of its scientists, the hopes of its children." - Dwight D. Eisenhower

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)

Programming Forums > Application Development > C

Pow() Function Doesn't Work[solved]