判断点是否在矩阵中

#include<stdio.h>
int main()
{
    double x,y;
    scanf("%lf %lf",&x,&y);
    //输入点的坐标
    double x1,y1,x2,y2;
    scanf("%lf %lf %lf %lf",&x1,&y1,&x2,&y2);
    //输入矩形对角线两个端点的坐标
    if((x-x1)*(x-x2)<=0 && (y-y1)*(y-y2)<=0)
    printf("是");
    else printf("否");
    return 0;
}