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pka
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pka
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01-29-2005
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07:22 PM
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pka
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Today,
06:24 PM
pka
replied to a thread
Solutions to an X1+X2...+X5=21 EQN
in
Probability / Statistics
That is solutions by generating functions. Suppose the question were: How many natural number solution are there for: u+v+w+x=14 subject to these...
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5 replies | 227 view(s)
Yesterday,
08:48 PM
pka
replied to a thread
Solutions to an X1+X2...+X5=21 EQN
in
Probability / Statistics
I know that you have done this the long way & correctly. I just wanted you to see THIS WEBPAGE There you will see the term 106x^{21} which...
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5 replies | 227 view(s)
Yesterday,
08:10 PM
pka
replied to a thread
Seating indistinguishable twins
in
Probability / Statistics
A many a textbook calls this the "MISSISSIPPI" problem. How ways can you rearrange that word? If it were MI_1S_1S_2I_2S_3S_4I_3P_1P_2I_4 it is no...
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5 replies | 232 view(s)
Yesterday,
04:23 PM
pka
replied to a thread
CodeCogs Jam Up
in
Math Odds & Ends
Posting images sideways and/or upside-down is not a simple mistake. It is a disregard for the person(s) from whom one is asking for help.
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24 replies | 431 view(s)
Yesterday,
04:14 PM
pka
replied to a thread
How many permutations of the letters ABCDEFG contain the string BCD?
in
Probability / Statistics
Here is a very useful website for looking up mathematical terms & concepts/ Because you are coming back, if I were you I wound bookmark the site....
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7 replies | 211 view(s)
11-16-2018,
11:27 PM
pka
replied to a thread
CodeCogs Jam Up
in
Math Odds & Ends
Sorry but I don't understand jest in this context. But I all for banning anyone who post a sideways/upside-down image.
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24 replies | 431 view(s)
11-16-2018,
09:00 PM
pka
replied to a thread
CodeCogs Jam Up
in
Math Odds & Ends
I will argue the exact opposite to the above. Even having multiple degrees in mathematical sciences, once I began using LaTeX I found the I was...
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24 replies | 431 view(s)
11-16-2018,
09:26 AM
pka
replied to a thread
Questions about the formal definition of the limit of a series
in
Calculus
You are really confused! If a_n converges to L then: 1) if \varepsilon>0 2) \exists N_1\in\mathbb{N}^+ 3) so that if n\ge N_1 then...
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4 replies | 190 view(s)
11-15-2018,
12:30 PM
pka
replied to a thread
how many 3-digit numbers possible from a set of : 0,3,4,5,6,7
in
Probability / Statistics
First & most importantly, a three digit numbers must not have zero in the hundredth position. The permutation of six taken three...
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8 replies | 233 view(s)
11-15-2018,
10:38 AM
pka
replied to a thread
Percentage of Increase/Decrease: If a regular haircut costs $5.00 in 1965...
in
Finance/Business Math
Suppose the NP stands for new price & OP stands for old price. Then the percent of increase/decrease is \dfrac{NP-OP}{OP}.
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6 replies | 172 view(s)
11-11-2018,
09:04 PM
pka
replied to a thread
Series Question: Divergence or Converence of sum[n=1,infty][(-1)^{n+1} (n^2/(n^3+1))]
in
Calculus
It does not matter even it is not decreasing for the first 10^{10} terms. Just that it is decreasing from some term on.
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6 replies | 276 view(s)
11-11-2018,
08:10 PM
pka
replied to a thread
Series Question: Divergence or Converence of sum[n=1,infty][(-1)^{n+1} (n^2/(n^3+1))]
in
Calculus
Is it clear to you that if x>2 then \dfrac{-x^4+2x}{(x^3+1)^2}<0~? What does a negative derivative tell us about the function?
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6 replies | 276 view(s)
11-11-2018,
06:04 PM
pka
replied to a thread
simple inequality problem: integer solutions for 4=<a<7, -5<b=<3
in
Intermediate/Advanced Algebra
WHY is this true \bf{-35<a\cdot b<21}~?
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5 replies | 241 view(s)
11-11-2018,
10:17 AM
pka
replied to a thread
Logs: Solving logarithmic equation log_4 x - log_4 6 = 3
in
Intermediate/Advanced Algebra
\begin{align*}\dfrac{6}{x}&=\dfrac{64}{1}\\\ \; \\\dfrac{x}{6}&=\dfrac{1}{64}\\ \; \\x&=\dfrac{6}{64} \end{align*}
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20 replies | 659 view(s)
11-10-2018,
10:02 PM
pka
replied to a thread
Quick Question: Let f(x) = 6+7x+2cosx. Find(f^-1)'(8)
in
Calculus
I am fully aware that boardr says that s/he knows the 'formula'. But many years experience taught me that can be useless. The same experience...
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14 replies | 487 view(s)
11-10-2018,
08:02 PM
pka
replied to a thread
Quick Question: Let f(x) = 6+7x+2cosx. Find(f^-1)'(8)
in
Calculus
Lets take a tour through the derivation. Recall the derivative of a composition. Suppose that f~\&~g are both differentiable then D_x=D_x If that...
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14 replies | 487 view(s)
11-10-2018,
03:31 PM
pka
replied to a thread
Quick Question: Let f(x) = 6+7x+2cosx. Find(f^-1)'(8)
in
Calculus
Because you have shown us none of your thinking, despite your being asked, it is hard to know what you fail to understand. f(x) = 6+7x+2\cos(x), do...
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14 replies | 487 view(s)
11-09-2018,
03:09 PM
pka
replied to a thread
Area enclosed between y= -6x^2+10x and the line y= -8x+12
in
Calculus
Yes it does! You said the answer is 1. Well look HERE. Surely in your calculus notes you have the upper curve minus lower curve method of finding...
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10 replies | 374 view(s)
11-09-2018,
10:43 AM
pka
replied to a thread
Area enclosed between y= -6x^2+10x and the line y= -8x+12
in
Calculus
The integral \int_1^2 { \leftdx} gives the shaded area. Why is that enough?
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10 replies | 374 view(s)
11-08-2018,
10:50 PM
pka
replied to a thread
Logs: Solving logarithmic equation log_4 x - log_4 6 = 3
in
Intermediate/Advanced Algebra
\begin{align*}\dfrac{x}{6}&=64 \\x&=64\cdot 6 \end{align*} What is hard to understand about that? Please tell us in detail.
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20 replies | 659 view(s)
11-08-2018,
06:01 PM
pka
replied to a thread
Logs: Solving logarithmic equation log_4 x - log_4 6 = 3
in
Intermediate/Advanced Algebra
Have you studied the logarithmic properties? For example, are you conformable with \log_4(x)-\log_4(6)=\log_4\left(\dfrac{x}{6}\right)~? Or do...
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20 replies | 659 view(s)
11-07-2018,
05:56 PM
pka
replied to a thread
Definite Integration: int[3,9][f(x)]dx = 7; find int[3,9][2*f(x) + 1]dx
in
Calculus
I find your lack of grouping symbols makes this hard to read. If this is a correct reading then: \large{\int_3^9 {(2f(x) + 1)dx} = 2\int_3^9...
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4 replies | 411 view(s)
11-07-2018,
02:25 PM
pka
replied to a thread
I don't get this? "In August 2013, there were more than 119,000 people on wait list"
in
Beginning Algebra
We must assume the no one is waiting for both. \begin{align*}K+L&=113162 \\L&=K-81528\\K+(K-81528)&=113162 \end{align*} BTW: This gives K=97345...
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4 replies | 422 view(s)
11-05-2018,
07:05 PM
pka
replied to a thread
probability of getting corrct clothes in dry cleaning
in
Probability / Statistics
Yes I did. Because your question is utter nonsense. It has no answer. The shirts cannot be identical in every way and yet be identified by its owner.
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12 replies | 347 view(s)
11-05-2018,
05:23 PM
pka
replied to a thread
probability of getting corrct clothes in dry cleaning
in
Probability / Statistics
O.K. Lets clean it up. There are four shirts that are identical in every way except the owner name in inked in the collar. After laundering the...
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12 replies | 347 view(s)
11-05-2018,
04:28 PM
pka
replied to a thread
probability of getting corrct clothes in dry cleaning
in
Probability / Statistics
That is nonsensical. If the shirts are identical it makes no to ask if a person get his own shirt? How would he know. If you say that the shirts are...
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12 replies | 347 view(s)
11-05-2018,
03:15 PM
pka
replied to a thread
De Moivre's Theorem: cos4x in the form: cos4x = Acos(4x) + Bcos(2x) + C
in
Intermediate/Advanced Algebra
\begin{align*}\cos(4x)&=\cos\\&=\cos^2(2x)-\sin^2(2x)\\&=^2-^2\\&=\cos^4-2\sin^2(x) \cos^2(x)+\sin^4(x)...
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2 replies | 323 view(s)
11-05-2018,
01:59 PM
pka
replied to a thread
probability of getting corrct clothes in dry cleaning
in
Probability / Statistics
As stated the question is hard to read despite what you say. That given answer is total nonsense. The correct answer is 1-\dfrac{\mathscr{D} _ 4...
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12 replies | 347 view(s)
11-05-2018,
09:49 AM
pka
replied to a thread
finding angle alpha in quadrilateral ABCD (please see picture)
in
Geometry and Trig
ketanco, Please clarify what the notation in the diagram means. For example: it clear that \overline{DC} bisects \angle C. BUT do the 'dots' mean...
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9 replies | 463 view(s)
11-03-2018,
03:48 PM
pka
replied to a thread
Looking for clarification on this equation: solve y=-12.34ln(x)+133.72 for x
in
Intermediate/Advanced Algebra
Notation to make matters easy: \exp(f(x))=e^{f(x)} ...
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7 replies | 344 view(s)
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About pka
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About pka
Biography:
Retired university mathematics professor & division chair.
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“A professor is someone who talks in someone else’s sleep”
W.H. Auden
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07:22 PM
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