【单选题】The writer and teacher as well as some of the students_____ a chance to go abord last year.
【简答题】已知函数f(x)=-x 3 +ax 2 +b(a,b∈R). (I)当a>0时,求函数y=f(x)的极值; (II)若函数y=f(x)的图象上任意不同的两点连线的斜率都小于2,求证:- 6 <a< 6 ; (III)对任意x 0 ∈[0,1],y=f(x)的图象在x=x 0 处的切线的斜率为k,求证:1≤a≤ 3 是|k|≤1成立的充要条件.
【单选题】设函数 在点x=0处连续,当x0时 则( )
【简答题】已知函数f(x)= 2x+3(当x≠0时) a(当x=0时) ,点在x=0处连续,则 lim x→∞ a n 2 +1 a 2 n 2 +n =______.
【单选题】分析从初级听觉传来的信号,翻译其意义的皮层区是:
【简答题】Fengshui was once an important part of traditional Chinese culture and emphasizes the harmonious of humans and their environment.
【单选题】在家用冰箱中,家禽肉的冷冻保管温度一般在
【单选题】分析从初级听觉传来的信号,翻译其意义的皮层区