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by nona.m.nona
Wed Jul 01, 2015 12:07 am
Forum: Discrete Math
Topic: solve this difficult number sequence
Replies: 3
Views: 51

Re: solve this difficult number sequence

There does appear to be another instance of this question, proposed at nearly the same point in time five years past. The second instance ( here ) may be a repost of the poker-forum original which, as noted in the previous reply, may have contained an error -- and indeed may have have been a jape. T...
by nona.m.nona
Tue Jun 16, 2015 5:51 pm
Forum: Discrete Math
Topic: i need this to be proved really QUICK!
Replies: 1
Views: 115

Re: i need this to be proved really QUICK!

Prove that every tree graph has at least two vertexes with degree of one. There are many discussions of this exercise. You may find some of the following to be helpful: ⋅  StackExchange: Tree has at least two vertices of degree 1 ⋅  Homework Solutions (see Exercise 1) ⋅&nbs...
by nona.m.nona
Fri Jun 12, 2015 7:39 pm
Forum: Advanced Algebra ("pre-calculus")
Topic: problem how to find solutions to hyperbola equation
Replies: 1
Views: 63

Re: problem how to find solutions to hyperbola equation

A problem I have asks for the equations for the asymptotes of a hyperbola with this equation: [(x-3)^2/81] - [(y+7)^2/49] = 1 The answer given is: (-18, -7); (0,-7) I don't understand this You are quite correct that these points cannot possibly be the required equations of asymptotes. In fact, thes...
by nona.m.nona
Wed May 20, 2015 12:39 pm
Forum: Advanced Algebra ("pre-calculus")
Topic: Finding an nth degree polynomial
Replies: 1
Views: 157

Re: Finding an nth degree polynomial

Suppose the division of f(x) by x-5 gives a quotient Q(x) and remainder R of 23. (b) Suppose Q(9) = 4; find f(9) One may "plug in" to what has already been determined by the conditions of the exercise. The exercise provides that: . . . f(x)\, =\, q(x)(x\, -\, 5)\, ...
by nona.m.nona
Wed May 20, 2015 12:29 pm
Forum: Intermediate Algebra
Topic: Substituting a Zero into a negative variable
Replies: 8
Views: 247

Re: Substituting a Zero into a negative variable

so i'm trying to substitute this (1x^2 + 0x + 1 = 0) into the quadratic formula here is a reference link for the quadratic formula: http://postimg.org/image/8wx31enwf/ the part i'm not sure about is.. substituting 0 where -b is... what exactly happens What happens is that, where the Formula has a &...
by nona.m.nona
Mon May 04, 2015 2:14 am
Forum: Uncategorized
Topic: How did Babylonians divide circle into 360 ?
Replies: 2
Views: 251

Re: How did Babylonians divide circle into 360 ?

How did ancient people divide circle into 360 ? equal parts It is quite possible that nobody knows; this information may have been lost. But one method might have started with inscribing a pentagon using only a compass and straightedge . This would split the circumference into five equal arcs, each...
by nona.m.nona
Wed Mar 25, 2015 11:57 am
Forum: Advanced Algebra ("pre-calculus")
Topic: Having difficulty with exponent equation
Replies: 1
Views: 439

Re: Having difficulty with exponent equation

6561^{2x^2\, -\, x}\, =\, 27 This is what I started: 81^((x^2)-x)=3^3 Some steps appear to be missing. I believe, between the two lines above, you have converted the 6561 into 81^2. However, since the 2 does not factor out of 2x^2 - x, it cannot be "taken out" and applied to the base sepa...
by nona.m.nona
Fri Feb 27, 2015 4:04 pm
Forum: Discrete Math
Topic: Find two proofs for the identity
Replies: 4
Views: 778

Re: Find two proofs for the identity

Using a combinatorial argument, prove the following identity: \binom{2n}{2}\,=\,2\,\binom{n}{2}\,+\,n^2 To use a "combinatorial argument", one must consider sets of elements. On the left-hand side: Consider a set with 2n elements, and pick two elements at a time. This may be done in C(2n,...
by nona.m.nona
Sun Feb 15, 2015 3:05 am
Forum: Calculus
Topic: Finding the derivative of arctan
Replies: 1
Views: 518

Re: Finding the derivative of arctan

y=arctan sqrt[(1+x)/(1-x)] what i did: let u= sqrt[(1+x)/(1-x)] du=1/2 [(1-x)/(1+x)]^1/2 [{(1+x)(-1)-(1-x)}/(1+x)^2]dx I solved this problem many times, but I don't get the right answer.... Where did you take the derivative of the inverse tangent? What did you get for your answer? What is "the...
by nona.m.nona
Fri Jan 30, 2015 7:37 pm
Forum: Matrix (Linear) Algebra
Topic: is A C B^T = B C^T A^T ?
Replies: 1
Views: 559

Re: is A C B^T = B C^T A^T ?

I don't understand how A C B^T + B C^T A^T = 2 A C B^T This may be rearranged as: A C B T + B C T A T = A C B T + A B C T This results in: B C T A T = A B C T Two properties of transpositions are that the transpose of a transpose is the original matrix, and that the transposition of a product resul...

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