【简答题】设 , 为直角坐标平面内x轴.y轴正方向上的单位向量,若 ,且 (Ⅰ)求动点M(x,y)的轨迹C的方程; (Ⅱ)设曲线C上两点A.B,满足(1)直线AB过点(0,3),(2)若 ,则OAPB为矩形,试求AB方程.
【单选题】—How soon will he come back? — . [ ]
【简答题】After three days waiting, there was some doubt in the mother's mind______ the police could find her lost child or not.
【简答题】After spending three days in a wheelchair, I was ready to quit. Not only did I have to battle cracked (裂缝的) and uneven (不平的) pavements, I had to deal with the bad attitude of pedestrians (行人) and a co...
【简答题】货垛的规范要求主要是指“五距”,即 、 、 、 和灯距。
【简答题】设直线y=kx与椭圆 x 2 4 + y 2 3 =1 相交于A、B两点,分别过A、B向x轴作垂线,若垂足恰为椭圆的两个焦点,则k等于______.
【简答题】将直线y=2x-3向右平移3个单位,再向上平移1个单位,求平移后的直线的关系式. 在直线y=2x-3上任取两点A(1,-1),B(0,-3). 由题意知: 点A向右平移3个单位得A′(4,-1);再向上平移1个单位得A″(4,0) 点B向右平移3个单位得B′(3,-3);再向上平移1个单位得B″(3,-2) 设平移后的直线的关系式为y=kx+b. 则点A″(4,0),B″(3,-2)在该直线上, ...
【简答题】阅读理解。 After spending three days in a wheelchair, I was ready to quit. Not only did I have to battle cracked and uneven pavements, I had to deal with the bad attitude of pedestrians and a cold rain. Bu...
【简答题】货垛的规范要求主要是指“五距”,即( )、( )、( )、( )、( )。