1. The leading digit of a number is the leftmost digit occurring in that number. For example, the leading digit of 45526 is 4. What is the leading digit of 4^11213??
Ans: 7
2. If the 4th term of a geometric progression is a and the 8th term is b, then the first term is...???
Ans: a^7/4b^-3/4
3. If sin X + cos X = 0, find the value of tan X + 1 / tan X.
Ans: -2
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2010-12-24 3:23 am
回答 (2)
2010-12-24 3:56 am
2010-12-24 3:56 am
1 log(4^11213)=11213log4=6750.8987
所以4^11213是6750位數。然後LEADING DIGIT 是可以由4^11213/10^6750計算得到。因log(4^11213/10^6750)=0.8987。因此4^11213/10^6750=10^(0.8987)=7.9192。因此LEADING DIGIT 是7
2 令首項T﹐公差r。Tr^3=a,Tr^7=b
r=(a/T)^(1/3)。因此T(a/T)^(7/3)=b
a^(7/3)T^(-4/3)=b
T=[a^(7/3)/b]^(3/4)
T=a^(7/4)b^(-3/4)
3 sin X + cos X = 0, find the value of tan X + 1 / tan X.
tan X + 1 / tan X
=sinx/cosx+cosx/sinx
=(-1)+(-1)
=-2
所以4^11213是6750位數。然後LEADING DIGIT 是可以由4^11213/10^6750計算得到。因log(4^11213/10^6750)=0.8987。因此4^11213/10^6750=10^(0.8987)=7.9192。因此LEADING DIGIT 是7
2 令首項T﹐公差r。Tr^3=a,Tr^7=b
r=(a/T)^(1/3)。因此T(a/T)^(7/3)=b
a^(7/3)T^(-4/3)=b
T=[a^(7/3)/b]^(3/4)
T=a^(7/4)b^(-3/4)
3 sin X + cos X = 0, find the value of tan X + 1 / tan X.
tan X + 1 / tan X
=sinx/cosx+cosx/sinx
=(-1)+(-1)
=-2
收錄日期: 2021-04-23 23:23:59
原文連結 [永久失效]:
https://hk.answers.yahoo.com/question/index?qid=20101223000051KK01079