Question

c语言求助 用if语句遍程序，输入x后按下式计算y值并输出结果 y=x+2x^+10 (0<=x<=8) y=x-3x^3-9(x<0或x>8)

#include<stdio.h>
int main()
{
float x,y;
scanf("%f",&x);
if(0<=x<=8);
y=x+2*x*x+10;
printf("%f",y);
else{
y=x-3*x*x*x-9;
printf("%f",y);
}
return 0;
}

Answer 1

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

int main ( )
{
double x,y;
printf("input x:");
scanf("%lf",&x);
if (x<1) y = 2*x+3;
else if (x>=10) y= sqrt( 3*x-4);
else y=2*x*x-1;
printf("y=%8.3f\n",y);

return 0;
}