某校开展“爱我海西、爱我家乡”摄影比赛,9位评委为参赛作品A给出的分数如茎叶图所示.记分员在去掉一个最高分和一个最低分后,算得平均分为91,复核员在复核时,发现有一个数字(茎叶图中的x)无法看清,若记分员计算无误,则数字x应该是__________.
函数的定义域是
A class collects $50 to buy flowers for a classmate who is in the hospital. Roses cost $3 each, and carnations cost $2 each. No other flowers are to be used. How many different bouquets could be purchased for exactly $50?_______
若a>0,a1,F(x)为偶函数,则G(x)=F(x)·log(x+)是_______函数(填“奇”或“偶”),它的图像关于______对称。
已知f(x)=x+(a-1)x+a在区间上是增函数,则a的取值范围是______