Code:
#include <stdio.h>
#include <stdlib.h>
#include <math.h>

double sqrt_function (double number);

int main (void)
{
	double val;
	double p = 0;
	printf("input number: ");
	scanf("%lf", &val);

	p = sqrt_function (val);	

	printf("\n\n\t%f\n\n", p);
	return 0;
}

double sqrt_function (double number)
{
	sqrt (number);

	return;
}
please, with -Wall and -lm on Debian linux...

Code:
jamie@box6:~/git/square_c$ cc -Wall -lm lost.c
lost.c: In function ‘sqrt_function’:
lost.c:24:2: warning: ‘return’ with no value, in function returning non-void
  return;
  ^~~~~~
lost.c:20:8: note: declared here
 double sqrt_function (double number)
        ^~~~~~~~~~~~~
jamie@box6:~/git/square_c$
code works, what would be a better way to write the sqrt_function?

Thanks!