White entry have the function F (x) = (x + 1) ^ 2, and G (x) = 2x + 1. X input value calculating F (G (x)).

#include<stdio.h>
#include<math.h>
void main()
{
	float x,y;
	printf("Please input x\n");
	scanf("%f",&x);
	y=2*x+1;
	y=(float)pow(y+1,2);
	printf("%f",y);
}

Used a square, we need to add the standard math library functions #include <math.h>