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pka
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pka
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01-29-2005
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12:36 AM
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pka
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Yesterday,
12:22 AM
pka
replied to a thread
How would one go about solving this problem?
in
Intermediate/Advanced Algebra
Speaking of LaTeX formattingLaTeX it ain't hard to learn. Once learned it is done, \dfrac{2d^2 -d-10}{d^2 +7d+10}=\dfrac{d^2 -4d+3}{d^2 +2d-15} May...
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6 replies | 173 view(s)
01-20-2019,
07:55 PM
pka
replied to a thread
Sinus domain: y = sin(alpha) What is the domain of y is between -1 to 1?
in
Geometry and Trig
|1|=1 therefore if f(x)\le|1| then f(x)\le 1 period. I think you mean if |f(x)|\le 1 then -1\le f(x)\le 1 do you not?
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23 replies | 1088 view(s)
01-19-2019,
10:55 PM
pka
replied to a thread
Diameter and chord in a circle
in
Beginning Algebra
Like Prof Peterson, I cannot read your image. Here is mine, but you must bare with me it is by no means drawn accurately. O is the circle's center,...
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3 replies | 284 view(s)
01-19-2019,
07:23 PM
pka
replied to a thread
Complex number algebra
in
Beginning Algebra
Because {\bf{i}}^2=-1 we now have (4A-2B)+(2A+4B){\bf{i}}=6+7\bf{i} Setting real parts equal & imaginary parts equal. 4A-2B=6\\2A+4B=7 Solve...
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12 replies | 389 view(s)
01-19-2019,
12:22 AM
pka
replied to a thread
What is the assumed base when applying logs to both sides?
in
Intermediate/Advanced Algebra
What is the point of this? Do you understand (\forall y)\left~? So \{(x,y): x\le 0\} is a subset of the solution for x<5^y What other pairs...
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11 replies | 402 view(s)
01-18-2019,
04:23 PM
pka
replied to a thread
Complex number algebra
in
Beginning Algebra
To Jimi2404, Please double check your post. As posted the equation has no definite solution. See here. I suppect it should be...
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12 replies | 389 view(s)
01-17-2019,
01:40 PM
pka
replied to a thread
Parametric to Cartesian
in
Intermediate/Advanced Algebra
You can see the graphs; GRAPH I GRAPH II Do they match?
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6 replies | 219 view(s)
01-17-2019,
01:20 PM
pka
replied to a thread
How many combinations of sets of 6?
in
Arithmetic
At least you could be honest: you came here for the answer and not really help. \dbinom{11}{6}=462 ways to pick six from eleven. SEE HERE.
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8 replies | 496 view(s)
01-16-2019,
03:17 PM
pka
replied to a thread
How many combinations of sets of 6?
in
Arithmetic
Please provide us with what you have done so that we can know how to help. As for online caculators: SEE HERE...
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8 replies | 496 view(s)
01-16-2019,
01:50 PM
pka
replied to a thread
Choose 24 of 78,000 prime numbers
in
Probability / Statistics
I suspect that the OP is a poor translation into English. Therefore, I think that the word prime should be whole number, integer, counting or...
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4 replies | 419 view(s)
01-16-2019,
01:00 AM
pka
replied to a thread
Negative roots when simplifying surds
in
Pre-Algebra
I did a very poor job explaining our objections. No one would ever need to use \sqrt{-16 i }. On the other hand there could be a need to solve...
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20 replies | 881 view(s)
01-15-2019,
01:46 PM
pka
replied to a thread
Negative roots when simplifying surds
in
Pre-Algebra
. At meetings we would have new jokes about exponents. Prof Paterson has address this above. The objection is this \sqrt{-16}=\pm 4\bf{i}. I dare...
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20 replies | 881 view(s)
01-15-2019,
11:29 AM
pka
replied to a thread
Negative roots when simplifying surds
in
Pre-Algebra
No, because the any real number has a real root if the index is odd. Example \large\sqrt{-32}=-2
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20 replies | 881 view(s)
01-14-2019,
11:40 PM
pka
replied to a thread
Negative roots when simplifying surds
in
Pre-Algebra
I have had issues with this my whole active research & teaching life. I had problems with students in my complex variables classes with the use of...
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20 replies | 881 view(s)
01-13-2019,
09:36 PM
pka
replied to a thread
Proof for parallel lines
in
Geometry and Trig
angle This is a much better image for there is no implied additional information. Note that if m(\angle HAG)=\dfrac{\pi}{4} then m(arc...
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8 replies | 492 view(s)
01-12-2019,
05:13 PM
pka
replied to a thread
Predicting Card sequence
in
Probability / Statistics
The answer you have been given equals \left^{-1}
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10 replies | 462 view(s)
01-11-2019,
09:58 AM
pka
replied to a thread
Exactly two subspaces
in
Intermediate/Advanced Algebra
Please post what you understand about this question. For example: What are the two subspaces (some call them trivial) of any v-space? If v\in...
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1 replies | 351 view(s)
01-10-2019,
10:09 PM
pka
replied to a thread
Finding the inverse
in
Intermediate/Advanced Algebra
Please post a readable attachment. A sideways attachment is not readable.
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2 replies | 310 view(s)
01-10-2019,
04:26 PM
pka
replied to a thread
Perimeter inequality
in
Geometry and Trig
TO eligotas, If you will answer Prof Khan's question then I will show why the upper bound.
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3 replies | 190 view(s)
01-09-2019,
01:34 AM
pka
replied to a thread
The beahave of "infinity part"
in
Calculus
This is an honest if brutal answer which is no way meant to belittle you. You simply do not have a sufficient mathematical background to even begin...
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4 replies | 200 view(s)
01-08-2019,
02:54 PM
pka
replied to a thread
The beahave of "infinity part"
in
Calculus
If \mathop {\lim }\limits_{x \to \infty } f(x) = \infty then \left( {\forall n \in {\mathbb{Z}^ + }} \right)\left( {\exists x>n} \right)\left This...
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4 replies | 200 view(s)
01-08-2019,
02:06 PM
pka
replied to a thread
probability of number ending in 1
in
Probability / Statistics
What is probability that a randomly selected positive integer ends in 3\text{ or } 7~? Is it \dfrac{2}{10}~? What is probability that a randomly...
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1 replies | 88 view(s)
01-08-2019,
01:26 PM
pka
replied to a thread
Solve: cos^−1(2x) + sin^−1(x) = π/3
in
Geometry and Trig
It appears as if you are dividing when there is no division. It should be 2x\sqrt{1-x^2}-x\sqrt{1-4x^2}=\dfrac{1}{2} But that is a beast of an...
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19 replies | 638 view(s)
01-07-2019,
10:20 PM
pka
replied to a thread
a hard equation, please help!
in
Calculus
It is just not that complicated. I posted this . Now 251-1=250=2\cdot 5^3 let x=1,~y=5,~\&~z=5. Thus (2\cdot 1)^3+(2\cdot 5)^3+(2\cdot 5)^3=2008
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10 replies | 392 view(s)
01-07-2019,
09:29 PM
pka
replied to a thread
Solve: cos^−1(2x) + sin^−1(x) = π/3
in
Geometry and Trig
To:Jomo here is the OP That was my clue.
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19 replies | 638 view(s)
01-07-2019,
08:07 PM
pka
replied to a thread
standard limit indication
in
Calculus
I was able to do this after understanding your notation. \mathop{\lim }\limits_{x \to \infty } \left = \mathop {\lim }\limits_{x \to \infty }...
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5 replies | 281 view(s)
01-07-2019,
06:47 PM
pka
replied to a thread
Solve: cos^−1(2x) + sin^−1(x) = π/3
in
Geometry and Trig
\begin{align*} \arccos (2x) + \arcsin (x) &= \frac{\pi }{3}\\ \cos (\arccos (2x) + \arcsin (x)) &= \cos \left( {\frac{\pi }{3}} \right)\\ \cos...
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19 replies | 638 view(s)
01-07-2019,
01:27 PM
pka
replied to a thread
a hard equation, please help!
in
Calculus
If we follow the hint. 2008=2^3\cdot 251 so 8x^3 + 8y^3 + 8z^3 = 8\cdot 251 or x^3 + y^3 + z^3 = 251
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10 replies | 392 view(s)
01-06-2019,
09:51 PM
pka
replied to a thread
Different solutions to one trig equation?
in
Geometry and Trig
Because of the layout of your post it is hard to follow your questions. That said, in #3 you divided by the \sin(x) which eliminated a complete set...
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6 replies | 308 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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