【简答题】已知关于x,y的方程C:x 2 +y 2 -2x-4y+m=0. (1)若方程C表示圆,求m的取值范围; (2)若圆C与圆x 2 +y 2 -8x-12y+36=0外切,求m的值; (3)若圆C与直线l:x+2y-4=0相交于M,N两点,且 |MN|= 4 5 5 ,求m的值.
【简答题】A. Become more touchy-feely B. Eat more chocolate every day C. Eat less sodium and salt D. Eat potassium-rich foods
【单选题】______ you eat butter, cream and chocolate, ____ you will become.
【单选题】已知圆C:(x-2) 2 +(y-1) 2 =25,过点M(-2,4)的圆C的切线l 1 与直线l 2 :ax+3y+2a=0平行,则l 1 与l 2 间的距离是( )
【单选题】过点M(-2,4)作圆C:(x-2) 2 +(y-1) 2 =25的切线l,且直线l 1 :ax+3y+2a=0与l平行,则l 1 与l间的距离是( )
【判断题】过程创新是指产品的生产技术的变革,它包括新工艺、新设备和新的组织管理方式
【简答题】A. Become more touchy-feely B. Eat some chocolate every day C. Eat less sodium and salt D. Eat potassium-rich foods
【多选题】等速运动测定仪可以提供的肌力测试形式包括()
【简答题】However life strikes you,cities worldwide have been growing even more rapidly.Some of this growth has occurred in the developed world,but the most dramatic increase has been in the Third World.A...
【单选题】平移坐标轴,将坐标原点移至 ,则点 在新坐标系中的坐标为 ( )