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float fun (float ); //求方程的解的函数
float fun (float x)
{
float y;
y = 2*x*x*x-4*x*x+3*x-6;
return y;
}
int main (void)
{
float l,r,x;
do
{
printf("input x1 x2(-10~10):");
scanf("%f %f",&l,&r);
}while ( fun(l)*fun(r)>0 ); //判断输入的范围内是否有解
while ( (abs(r-l))>0.00001 ) //解的精度，可按要求调整
{
x = (l+r)/2;
if ( fun(x)>0 )
{
r = x;
}
else if ( fun(x)<0 )
{
l = x;
}
else
{
break;
}
}
printf("result:%lf\n",x);
return 0;
}
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