【单选题】Experts eventually decided to investigate ______ .
A.
because they did not believe that pumas existed in England
B.
because they wanted a puma for the London Zoo
C.
when a woman saw a puma in a small village
D.
because people's descriptions of the puma had a lot in common
【单选题】Experts eventually decided to investigate _____.
A.
Because they did not believe that pumas existed in England
B.
Because they wanted a puma for the London Zoo
C.
When a woman saw a puma in a small village
D.
Because people's description of the puma had a lot in common
【简答题】下图的曲线C 1 、C 2 、C 3 、C 4 是指数函数y=a x 的图象,而a∈{ , , ,π},则图象C 1 、C 2 、C 3 、C 4 对应的函数的底数依次是( )、( )、( )、( )。
【单选题】Experts eventually decided to investigate
A.
because they did not believe that pumas existed in England
B.
because they wanted a puma for the London Zoo
C.
when a woman saw a puma in a small village
D.
because people's descriptions or tne puma had a lot in common
【简答题】设X是赋范空间,f是X上的非零有界线性泛函。证明: E={x∈X:f(x)=‖f‖) 是X的非空闭凸子集且 inf(‖x‖:x∈E}=1
【单选题】小明用3%的可溶性淀粉溶液为底物,探究温度对唾液淀粉酶活性的影响。他设置了4组实验(除温度外其他条件均相同),待反应一段时间后取出试管,室温放置30分钟,加适量碘液,显色结果见下表(“+”越多,表示蓝色越深)。 根据实验结果,可知()
【简答题】计算:(1)若数列 a n = 1 n(n-1) ,求 lim n→∞ ( a 2 + a 3 + a 4 +…+ a n ) ; (2)若函数 f(x)= x -1 x?(x-1) (x>1) a+ 2 x (x≤1) 在R上是连续函数,求a的取值.