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更多“在SPAN配置过程中，如果SPAN浓度过高，应补加一定量EX…”相关的问题
判断下列函数的奇偶性．
(1)
(2)
(3)＜span name='maths'＞f(x)=\frac{x\sinx}{\cosx}＜/span＞]
A．increase
B．expansion
C．growth
D．prolongation
A precisely B instantly C initially D exclusively
The second research proved that
A．the life span of trees in the Amazon basin is much longer than others.
B．trees consume carbon dioxide until they die.
C．it takes hundreds of years for trees to purify atmosphere.
D．the carbon that trees consumed may return to the atmosphere in five years.
A) The penny which doubles itself every day for one month.
B) The time span of at least two million years in human history.
C) An illustration of the exponential growth rate given by the author.
D) The large amount of money you would luckily make after the fourth week.
设H为Hilbert空间，{un}为H的无穷标准正交基，对n=1，2，…，设Fn=span{u1，u2，…un}。若Pn为从H到F，，的正交投影．求证：
(a)任每一x∈H有Pnx→x。
(b)‖Pn-I‖不收敛到0。
A．The penny that doubles itself every day for one month
B．The time span of at least two million years in human history
C．An illustration of the exponent growth rate given by the author
D．The large amount of money you would luckily make after the fourth week
