DiscreteMaths (computing)

Cairo

New Member
anybody good in DiscreteMaths ?
i need ur help ....
im in hot water in DiscreteMaths, i think my logical thinking is too weak...
anybody can help me to improve it or give me some useful website...
 
Cairo said:
anybody good in DiscreteMaths ?
i need ur help ....
im in hot water in DiscreteMaths, i think my logical thinking is too weak...
anybody can help me to improve it or give me some useful website...

What in particular do you need help with

do you mean proofs?

Example prove 4 is a even number.

or do you me something like the following
~(xV~d) which in english is not(x or not D)

I did both in my discrete math class I took in college.
 
something like Mathematical Induction .....
the inductive step....
uahhh.....
hard to understand(headache) ....
like below

1+3+5+.......+(2n-1)=n^2

how to prove ?
 
Cairo said:
something like Mathematical Induction .....
the inductive step....
uahhh.....
hard to understand(headache) ....
like below

1+3+5+.......+(2n-1)=n^2

how to prove ?

i havent taken discrete math yet but if you take the sum of the series you end up with n^2. so its basically Epsilon(2n-1) from taken between the limits of i = 1 to i = n. thats a mathematical proof if its any help.
 
OK here how it works

Acording to induction you must prove 2 things

1) prove that n(1) is true
2) take N(k) and derive from it that N(K+1) is true.

Step one is easy

2(1)-1=1^2

Step two this is the hard step
You going to have to use your brain to figure out a way to do this

First you suppose N(k) is true
then we must prove N(k+1) is also true
1+....+(2(n+1))-1)=(n+1)^2
since S(k) we assume true
1+....+(2n-1)=N^2
then we can say the following
1+...+(2n-1)+(2(n+1)-1)
N^2+(2(n+1)-1) *note we said that (2n-1)=n^2 so we just making a subtitution
the rest is algebra
N^2+2n+2-1
n^2+2n+1
(n+1)^2 and now we have derive n+1 from n

there for by induction the statement holds true for all n 1 and above.

Feel free if you need me to clear anything up on how the induction works

Edit one more thing to explain why induction works

since we derive n(k+1) from n(k) then it implies that if N(1) is true then N(2) is true but N(2) implies that N(3) is true and so on for ever making induction a nice trick to prove infinite series in 2 steps only.


i havent taken discrete math yet but if you take the sum of the series you end up with n^2. so its basically Epsilon(2n-1) from taken between the limits of i = 1 to i = n. thats a mathematical proof if its any help.

I would not really conisder that a proof. You need to prove that the sum equal N^2. Acutrally that the entire point of the question. Epsilon(2n-1) form i=1 to i=n is just anouther way to write the problem. It does not acturally prove anything.
 
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