Are you beginner in problem solving?
Let's Solve 200 Beginner level problems with explanation video:
https://cutt.ly/200-Problems-interactive-coding-pdf
#include <stdio.h>
#include <math.h>
void main(){ int num, result; printf("Enter a number: "); scanf("%d",&num); result = sqrt(num); printf("Square root of %d = %d",num,result);
}

#include <math.h>
int main()
{	float number;	square = pow(number,2); //This returns number raised to the power 2	printf("The square of %f is %f", number, square);	return 0;
}

#include <stdio.h>
#include <math.h>>
int main() {	float number, square;	printf("Enter a number: ");	scanf("%f", &number);	square = number * number;	printf("square of the given number %f is %.2f", number, square); return 0;
}

#include <stdio.h>
int main()
{	float number;	printf("Enter a number: ");	scanf("%f", &number);	square = number * number;	printf("square of the given number %f is %f", number, square);	return 0;
}

ubuntu@ip-172-31-63-244:~/julien$ l
total 44
drwxrwxr-x 2 ubuntu ubuntu 4096 Mar 25 02:47 .
drwxrwxr-x 19 ubuntu ubuntu 4096 Mar 25 02:44 ..
-rw-rw-r-- 1 ubuntu ubuntu 89 Mar 25 02:44 0-print_z.c
-rw-rw-r-- 1 ubuntu ubuntu 132 Mar 25 02:44 1-print_alphabet.c
-rw-rw-r-- 1 ubuntu ubuntu 132 Mar 25 02:44 2-print_tebahpla.c
-rw-rw-r-- 1 ubuntu ubuntu 166 Mar 25 02:44 3-print_base16.c
-rw-rw-r-- 1 ubuntu ubuntu 162 Mar 25 02:44 4-positive_or_not.c
-rw-rw-r-- 1 ubuntu ubuntu 636 Mar 25 02:44 5-print_number.c
-rw-rw-r-- 1 ubuntu ubuntu 178 Mar 25 02:47 my_functions.h
-rw-rw-r-- 1 ubuntu ubuntu 76 Mar 25 02:44 print_char.c
-rw-rw-r-- 1 ubuntu ubuntu 1392 Mar 25 02:46 print_char.o
ubuntu@ip-172-31-63-244:~/julien$ gcc -Wall -pedantic -Werror -Wextra -std=gnu89 -c *.c
ubuntu@ip-172-31-63-244:~/julien$ l
total 68
drwxrwxr-x 2 ubuntu ubuntu 4096 Mar 25 02:47 .
drwxrwxr-x 19 ubuntu ubuntu 4096 Mar 25 02:44 ..
-rw-rw-r-- 1 ubuntu ubuntu 89 Mar 25 02:44 0-print_z.c
-rw-rw-r-- 1 ubuntu ubuntu 1400 Mar 25 02:47 0-print_z.o
-rw-rw-r-- 1 ubuntu ubuntu 132 Mar 25 02:44 1-print_alphabet.c
-rw-rw-r-- 1 ubuntu ubuntu 1408 Mar 25 02:47 1-print_alphabet.o
-rw-rw-r-- 1 ubuntu ubuntu 132 Mar 25 02:44 2-print_tebahpla.c
-rw-rw-r-- 1 ubuntu ubuntu 1408 Mar 25 02:47 2-print_tebahpla.o
-rw-rw-r-- 1 ubuntu ubuntu 166 Mar 25 02:44 3-print_base16.c
-rw-rw-r-- 1 ubuntu ubuntu 1464 Mar 25 02:47 3-print_base16.o
-rw-rw-r-- 1 ubuntu ubuntu 162 Mar 25 02:44 4-positive_or_not.c
-rw-rw-r-- 1 ubuntu ubuntu 1472 Mar 25 02:47 4-positive_or_not.o
-rw-rw-r-- 1 ubuntu ubuntu 636 Mar 25 02:44 5-print_number.c
-rw-rw-r-- 1 ubuntu ubuntu 2048 Mar 25 02:47 5-print_number.o
-rw-rw-r-- 1 ubuntu ubuntu 178 Mar 25 02:47 my_functions.h
-rw-rw-r-- 1 ubuntu ubuntu 76 Mar 25 02:44 print_char.c
-rw-rw-r-- 1 ubuntu ubuntu 1392 Mar 25 02:47 print_char.o
ubuntu@ip-172-31-63-244:~/julien$ ar -rc libschool.a *.o
ubuntu@ip-172-31-63-244:~/julien$ ar -t libschool.a
0-print_z.o
1-print_alphabet.o
2-print_tebahpla.o
3-print_base16.o
4-positive_or_not.o
5-print_number.o
print_char.o
ubuntu@ip-172-31-63-244:~/julien$ ranlib libschool.a
ubuntu@ip-172-31-63-244:~/julien$ cat main.c
void print_alphabet(void);
int main(void)
{ print_alphabet(); return (0);
}
ubuntu@ip-172-31-63-244:~/julien$ gcc main.c
/tmp/ccQa2r6L.o: In function `main':
main.c:(.text+0x5): undefined reference to `print_alphabet'
collect2: error: ld returned 1 exit status
ubuntu@ip-172-31-63-244:~/julien$ gcc main.c -L. -lschool -o alpha
ubuntu@ip-172-31-63-244:~/julien$ ./alpha
abcdefghijklmnopqrstuvwxyzubuntu
ubuntu@ip-172-31-63-244:~/julien$