题目

设函数，则使得成立的的取值范围为_____． 答案：【解析】 试题分析：依题意，建立如图所示平面直角坐标系，由已知得， ，  所以，，. 考点：1.平面向量的坐标运算；2.平面向量的线性运算；3.平面向量的数量积. A woman saw three old men sitting outside．She said，“I don’t think I know you，but you must be very hungry．Please collie in and have something to  1  ．’’ “We don’t go into a house   2  ，”they answered．“Why is that?” she asked． One of the old men said，“His name is Wealth（财富），this is Success，and I am Love．Now go in and   3  with your family which one of us you want in your house．" The woman went in and told her family all that happened．She said," Let's invite Wealth．We have been so   4   " Her husband disagreed," My clear, why don't we invite Success? Don't yon want me to be a successful man?" Then her daughter asked," Would it be   5  to invite Love? Our life ~ill then be filled with love!" In the end, the family decided to take the   6   advice． So the woman went out and asked, "Which one of you is   7   ? Please come in and be our guest．" Love got up and started walking to the house．The other two also go up and   8   him．Surprised, the lady asked Wealth and Success, "I   9 invite Love．Why are you coming along?" The two old men answered," If you invited Wealth or Success, the other two would have to   10   , but as you invite Love, wherever he goes, we go with him．Where there is Love, there is Wealth and Success．" 1．A．say                 B．eat              C．use 2．A．together             B．alone               C．crowdedly 3．A．play                 B．exercise            C．discuss 4．A．poor                B．rich               C．lucky 5．A．worse              B．better              C．less 6．A．father's             B．mother's           C．daughter's 7．A．Love                 B．Wealth             C．Success 8．A．left                  B．followed         C．stopped 9．A．only                 B．hardly           C．never 10．A．join in             B．go along with       C．stay out