# Search results

1. ### If variance is 0, then p(x=c) = 1 c is constant

I think it is easy but I can't figure it out. :( any help?
2. ### Recursive question

Suppoese T(0) = 1 T(n) = T(n-1) + root(T(n-1)) how many recursion does T(n) need to grow to the number k? can I get this? root(k) < m < c root(k) c is constant and m is the times we need for T(n) goes to k. Any help appreciated!!
3. ### Recursive question

Suppoese T(0) = 1 T(n) = T(n-1) + root(T(n-1)) how many recursion does T(n) need to grow to the number k? can I get this? root(k) < m < c root(k) c is constant and m is the times we need for T(n) goes to k. Any help appreciated!!
4. ### Probability questions?

How to calculate the probability of this questions? Supposed there are m bukcets, n balls. use function f(x) to decide which bucket the ball go. Supposed that the probability a ball going to 0-j is 0.9 and going to j -> m-1 is 0.1. What's the probability of for every bucket there is at...
5. ### NFA Problem

Is that possible using six states to draw a NFSA(NFA) to represent a string ending with a symbol which occured even times in this string(this string is consisted of only 0 and 1).. I thought that the regular expression is (0*10*1)*(0*10*1) + (1*01*0)*(1*01*0), It can be easy using 7 states to...
6. ### Does x->infiity (ln |cosx|)/x^2 exist?

Does x->infiity (ln |cosx|)/x^2 exist?? I can't apply apply L'Hopital here, since the limit of |cosx| doesn't exist.. Any hints appreciated..
7. ### Non-recursive formula

How to get a non-recursive formula for y(n): y(n)=1 (n=1 or 2) y(n)=0 (n=3 or 4) y(n)=(y(n-4) + y(n-3))/2 Any hints apprecaited..
8. ### Connectives homework

{<->, ~} is not a complete set of connectives.. It seems that we can't use Propostions P is all true and thus lead to contradition since ~ can make it false. Any suggestion?
9. ### How to work that out?

1) (C -> A) and (!C -> B) 2) (A and C) or (!C and B) I use the logic calculator and found these two formulas are logical equivalent, but I spend 2 hours there and still can't prove it because I can't eliminate one of the three items. Can anyone help me? Thanks in advance!
10. ### Prove the algorithm for LCM

algorithm to prove lcm: a:=m b:=n while a != b if a < b a:= a + m else b:= b + n //postcondition: a is the lcm(m,n) what's the loop invariant?I thought it is(not sure): lcm(ak, bk) = lcm(ak/m, bk/n) *lcm(m,n) I am not sure and also impossible to prove my loop invariant...
11. ### Help me about loop invariant of LCM

please help me, i was stuck in here 2 days!!! algorithm to prove lcm: a:=m b:=n while a != b if a < b a:= a + m else b:= b + n //postcondition: a is the lcm(m,n) what's the loop invariant?I thought it is(not sure): lcm(ak, bk) = lcm(ak/m, bk/n) *lcm(m,n) I am...
12. ### Integration Problem.

integrate ln(tanx)/sinxcosx dx I want to change to integrate csc2x ln(tanx) dx , still can't work it out. Any suggestions? THX
13. ### Non-trivial equation

1)write root(3)-1 in another way,and use this to produce a non-trivial equation for root(3) in terms of itself 2)suppose m,n(m,n is natural numbers) are such that m/n=root(3),use (1) to write root(3)as another combination of m and n. 3)use (2) to show that root(3) in not rational. Any...
14. ### Question about non-trivial equation

Q: write roo(3)-1 in another way,and use this to produce a non-trivial equation for root(3) in terms of itself.. I don't ever know what it means? Any hints appreciated.. thanx
15. ### How to prove there is no limit of cos1/x using theorm of limit

How to prove there is no limit(x->0) of cos1/x using theorm of limit? Anybody can give me some hints? thanks
16. ### A limit definition problem.

show by example that the stament for all d>0 there exists e>0 such that o<|x-a|<d -> |f(x）-L|<e is Not the definition of limit. would somebody give me a hint?