[計量] GWD19-2,9
Q2:
For which of the following functions f is f(x) = f(1-x) for all x?
A. f(x) = 1 - x
B. f(x) = 1 - x2
C. f(x) = x2 - (1-x)2
D. f(x) = x2(1-x)2
E. f(x) = x / (1-x)
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Answer: D 不懂題目??
Q9:
A certain computer program generates a sequence of numbers a1, a2, … ,
a n such that a1 = a2 = 1 and ak = ak-1 + 2ak-2 for all integers k such that
3 ? k ? n. If n > 6, then a7 = ?
A. 32
B. 43
C. 64
D. 100
E. 128
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Answer: B
a1 =a0+2a-1=1
a2 =a1+2a0= 1
a3=a2+2a1=1+2*1=3=2^1+1
a4=a3+2a2=3+2*1=5=2^2+1
a5=a4+2a3=5+2*3=11
a6=a5+2a4=11+2*5=21
a7=a6+2a5=21+2*11=43
找不出規則變化,有快速解法嗎?
感謝:)
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10/09 11:49, , 1F
10/09 11:49, 1F
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