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#151 Re: Help Me ! » Function » 2013-05-18 17:59:41

Thanks to both of you.

#152 Re: Help Me ! » Function » 2013-05-18 05:39:29

I have found these
f(0)=0
2x^2=f(x)+f(-x)
f(x-y)=f(x)+f(-y)-2xy
f(x+1)=f(x)+f(1)+2x
f(2x)=2( f(x)+x^2 )
f(-2x)=2( f(-x)+x^2 )
what do i do now?

#153 Help Me ! » Function » 2013-05-18 00:06:00

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What is the function f(x) if this equation holds for each real x,y:  f(x+y)=f(x)+f(y)+2xy  [i know f(x) is x^2,but how do i formally obtain it?]

#154 Re: Help Me ! » Urgent help needed in factorial » 2013-05-17 04:59:15

I'm getting 1005,1006,1007,1008,1009.Are these correct?

#155 Help Me ! » Urgent help needed in factorial » 2013-05-17 00:42:33

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Urgent help needed,obtain a number n such that n! has exactly 250  0's at right(if any).please show the method how you obtained n (or showed that there is no such n).

#156 Re: Help Me ! » Orthogonal projection » 2013-05-16 17:59:17

I thought of this method too.anyway thanks

#157 Re: Help Me ! » Orthogonal projection » 2013-05-16 16:27:52

Thanks,how did you derive the coordinates?I've thought of a way but it's complex.

#158 Help Me ! » Orthogonal projection » 2013-05-16 13:04:41

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Suppose y=2x+1 is a line on xy plane.(2,3) is a point,what are the coordinates of the orthogonal projection of point on the line?

#159 Re: Help Me ! » Logic gates » 2013-03-07 02:31:30

I was trying to memorize and explain the logic gates earlier and i thought of sets.if  U={1,0} and 1={{ }},0={ } and A AND B=A intersection B,A OR B=A union B,NOT A=A' then the idea seems to work.are these expressions valid?

#160 Help Me ! » Logic gates » 2013-03-06 04:11:33

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Replies: 4

Can logic gates be expressed using mathematical operations

#161 Re: Help Me ! » Convergence » 2013-02-26 22:19:52

Those are series tests i asked for sequence tests,sorry for disturabing.

#162 Help Me ! » Convergence » 2013-02-26 20:06:07

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Replies: 3

Are there tests to see if a sequence (not series) converges?

#163 Help Me ! » Limit and nagetive infinity » 2013-02-23 23:15:30

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Replies: 2

I know that limit of (1+1/n)^n as n approches infinity is e.the limit of (1+1/n)^n as n approches nagetive infinity is also e,but how do i prove that?

#164 Re: Help Me ! » Need help to prove » 2013-02-20 16:01:13

Oh yeah,sorry for disturbing

#165 Help Me ! » Need help to prove » 2013-02-20 13:16:42

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How can i prove this-for all x,y in N, if x^y=y^x then x=y.

#166 Re: Help Me ! » How do i write it » 2013-02-19 19:35:19

When do i use the brackets and what is the meaning of the 2 signs which look like v and upside-down v.

#167 Help Me ! » How do i write it » 2013-02-19 05:13:33

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How do i write this using logic symbols "for all natural number x there exists a unique y such that y is twice as x" ?

#168 Re: Help Me ! » Properties of addition » 2013-02-18 01:00:17

Thanks,by the way is R constructed the same way?

#169 Re: This is Cool » Induction » 2013-02-18 00:33:22

So,can this axiom be used to prove stuff for integers?

#170 Re: Help Me ! » Properties of addition » 2013-02-17 14:58:38

Never mind i found ways to prove commutative and associative law of addition of natural numbers in internet[though i'd appreciate it if anyone tells me how this is extended to Z,Q,R,..]

#171 Re: This is Cool » Induction » 2013-02-17 14:52:20

By (c) i stated that -1,-2,-3,-4,... are in S,the general axiom doesn't state that.

#172 This is Cool » Induction » 2013-02-17 14:14:37

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Hi, I think i have found a way to use induction for integer set too (don't know if it was discovered before this post) by extending the axiom of induction we get "if S is a subset of Z and (a) 0 belongs to S,(b) for n belonging to S (n+1) belongs to S,(c)for n belonging to S (n-1) belongs to S ,then S=Z." if I'm wrong I hope others will correct me.

#173 Help Me ! » Properties of addition » 2013-02-16 17:35:06

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I have a younger cousin who wants to know how to prove addition is commutative and associative for whole numbers .but i don't know how to do that,can anyone help?plus it'd be good if anyone can tell me how the proof is extended to other number sets.

#175 Re: Help Me ! » P-norm » 2013-02-15 23:54:13

Why isn't nagetive number or fractions<1 allowed?

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