C语言分段函数计算

#include <stdio.h>
#include <math.h>
int main()
{  
    float x,y,a;
 printf("请你输入x的值:\n");
 scanf("%f",&x);
 if (x<=-300)
    y=-1;
 if (x>=300)
    y=-1;
 else
    y=(x*x*x)/log10(x+2.6) ;
 
    printf("f(%0.03f)=%0.03f",x,y);
  
 return 0;
}