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karush
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Today,
04:42
MarkFL
replied to a thread
BBCode For Username HTML Markup
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Yesterday,
22:53
MarkFL
replied to a thread
Prove a number is divisible by a number?
in
Number Theory
Another approach would be to use the binomial theorem: 7^n1=(6+1)^n1=6\sum_{k=1}^{n}\left({n \choose k}6^{k1}\right)
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7 replies  81 view(s)
Yesterday,
14:51
MarkFL
replied to a thread
AlphaZero Crushes Chess
in
Chat Room
That's amazing! (Yes)
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2 replies  38 view(s)
Yesterday,
14:38
MarkFL
replied to a thread
limit of a series
in
Calculus
As suggested, I would continue on your current path, but I wanted to show how I would approach the problem... I would begin by expressing the...
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3 replies  44 view(s)
Yesterday,
11:59
MarkFL
replied to a thread
Need help with reversal of a calculation involving gravitational constant.
in
PreAlgebra and Algebra
It's actually: G=\frac{rV_e^2}{2M}
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6 replies  67 view(s)
Yesterday,
01:55
MarkFL
replied to a thread
Revenue and Cost and Profit Problem
in
Business Mathematics
To follow up: The axis of symmetry is: x=\frac{48}{2(2)}=12 We see that the profit function opens downward, and so the vertex is the...
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3 replies  44 view(s)
December 10th, 2017,
12:30
MarkFL
replied to a thread
Revenue and Cost and Profit Problem
in
Business Mathematics
Another approach would be to express your profit function in vertex form: P(x)=a(xh)^2+k where: P_{\max}=k
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3 replies  44 view(s)
December 10th, 2017,
00:57
MarkFL
replied to a thread
Revenue and Cost and Profit Problem
in
Business Mathematics
Your profit function is correct: P(x)=2x^2+48x108 Now, what I would do is find the axis of symmetry (since the vertex lies on this...
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3 replies  44 view(s)
December 9th, 2017,
17:06
MarkFL
replied to a thread
m2215b.14 Find the limiting velocity
in
Calculus
If the hyperbolic tangent factor goes to 1, then the terminal velocity $v_T$ must be: v_T=\sqrt{\frac{mg}{k}} Dimensional analysis shows that...
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13 replies  165 view(s)
December 9th, 2017,
16:59
karush
replied to a thread
m2215b.14 Find the limiting velocity
in
Calculus
presume unchanging but how is that going to give ft/sec
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13 replies  165 view(s)
December 9th, 2017,
15:05
MarkFL
replied to a thread
m2215b.14 Find the limiting velocity
in
Calculus
Yes, and so what does this tell you about the terminal velocity?
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13 replies  165 view(s)
December 9th, 2017,
15:00
karush
replied to a thread
m2215b.14 Find the limiting velocity
in
Calculus
$\displaystyle \lim_{{u}\to{\infty}}\tanh\frac{1e^{2u}}{1+e^{2u}} =\tanh(1)$
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13 replies  165 view(s)
December 9th, 2017,
08:12
MarkFL
replied to a thread
Need help with reversal of a calculation involving gravitational constant.
in
PreAlgebra and Algebra
Hello, and welcome to MHB, Edwin! (Wave) We are given: V_e=\sqrt{\frac{2GM}{r}} What do we get if we square both sides of the equation?
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6 replies  67 view(s)
December 8th, 2017,
20:08
MarkFL
replied to a thread
m2215b.14 Find the limiting velocity
in
Calculus
Yes, so what's the limit: \lim_{u\to\infty}\tanh(u)\,?
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13 replies  165 view(s)
December 8th, 2017,
18:11
karush
replied to a thread
m2215b.14 Find the limiting velocity
in
Calculus
$\displaystyle \tanh(u)\equiv\frac{e^{u}e^{u}}{e^{u}+e^{u}} \cdot\frac{e^{u}}{e^{u}}=\frac{1e^{2u}}{1+e^{2u}}$
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13 replies  165 view(s)
December 8th, 2017,
03:22
karush
replied to a thread [SOLVED]
M2215b.08 Find the volume of the solid (shell meithod)
in
Calculus
ok yes I think I distributed it on the practice test7 thank for your help again
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8 replies  97 view(s)
December 8th, 2017,
02:39
MarkFL
replied to a thread [SOLVED]
M2215b.08 Find the volume of the solid (shell meithod)
in
Calculus
Let's check your result using the washer method: V=\pi\left(\int_0^{\sin\left(\frac{\pi^2}{4}\right)}...
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8 replies  97 view(s)
December 7th, 2017,
23:40
karush
replied to a thread [SOLVED]
M2215b.08 Find the volume of the solid (shell meithod)
in
Calculus
\begin{align*}\displaystyle V&=\pi\int_0^{\Large{\frac{\pi}{2}}} \sin\left(x^2\right)2x\,dx\\ &= \pi\Biggr\cos(x^2)\Biggr_0^{\pi/2}\\ ...
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8 replies  97 view(s)
December 7th, 2017,
22:14
MarkFL
replied to a thread [SOLVED]
M2215b.08 Find the volume of the solid (shell meithod)
in
Calculus
You originally had the integrand correct, but when you corrected the limits, you changed the integrand such that the integral was still incorrect...
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8 replies  97 view(s)
December 7th, 2017,
21:05
karush
replied to a thread [SOLVED]
M2215b.08 Find the volume of the solid (shell meithod)
in
Calculus
this? $x=\sqrt{\sin^{1}\left(y\right)}$
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8 replies  97 view(s)
December 7th, 2017,
17:54
MarkFL
replied to a thread [SOLVED]
M2215b.08 Find the volume of the solid (shell meithod)
in
Calculus
Now, reverse the change you made to the integrand...
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8 replies  97 view(s)
December 7th, 2017,
17:51
karush
replied to a thread [SOLVED]
M2215b.08 Find the volume of the solid (shell meithod)
in
Calculus
\begin{align*}\displaystyle V&=\int_0^{\pi/2} x\left(\sin x^2\right)\ dx\\ \end{align*}
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8 replies  97 view(s)
December 7th, 2017,
17:49
MarkFL
replied to a thread [SOLVED]
M2215b.08 Find the volume of the solid (shell meithod)
in
Calculus
Examine your limits of integration more closely...:)
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8 replies  97 view(s)
December 7th, 2017,
17:28
karush
started a thread [SOLVED]
M2215b.08 Find the volume of the solid (shell meithod)
in
Calculus
$\tiny{M2215b.08}$ Find the volume of the solid \begin{align*}\displaystyle y&=\sin (x^2)\\ 0&\le x \le \frac{\pi}{2}\\ \end{align*} about the...
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8 replies  97 view(s)
December 7th, 2017,
14:28
MarkFL
replied to a thread
m2215b.14 Find the limiting velocity
in
Calculus
No, I was thinking more along the lines of: \tanh(u)\equiv\frac{e^{u}e^{u}}{e^{u}+e^{u}} What happens if you multiply that by: ...
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13 replies  165 view(s)
December 7th, 2017,
14:23
karush
replied to a thread
m2215b.14 Find the limiting velocity
in
Calculus
this? via WA $\displaystyle\frac{e^{\sqrt{x}}} {e^{\sqrt{x}}+e^{\sqrt{x}}} \frac{e^{\sqrt{x}}} {e^{\sqrt{x}}+e^{\sqrt{x}}} $
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13 replies  165 view(s)
December 7th, 2017,
13:44
MarkFL
replied to a thread
m2215b.14 Find the limiting velocity
in
Calculus
Okay, now the given velocity function is dimensionally consistent, given that $k$ has units of mass per length (can you demonstrate this?). In...
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13 replies  165 view(s)
December 7th, 2017,
13:36
karush
replied to a thread
m2215b.14 Find the limiting velocity
in
Calculus
ok appartently i left it off i have had no physics so this is very new don't know where the numbers come from
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13 replies  165 view(s)
December 7th, 2017,
13:29
MarkFL
replied to a thread
Require Edit Reason
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November 24, 1944 (73)
About karush
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December 9th, 2017
20:00 
karush
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Re: m2215b.14 Find the limiting velocity
by
MarkFL
presume unchanging but...
15:04 
MarkFL
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Re: m2215b.14 Find the limiting velocity
by
karush
Yes, so what's the...
14:53 
karush
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Re: m2215b.14 Find the limiting velocity
by
MarkFL
$\displaystyle...
December 8th, 2017
03:39 
MarkFL
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Re: M2215b.08 Find the volume of the solid (shell meithod)
by
karush
ok yes I think I...
December 7th, 2017
23:51 
MarkFL
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Re: M2215b.08 Find the volume of the solid (shell meithod)
by
karush
\begin{align*}\displaysty...
17:50 
karush
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Re: M2215b.08 Find the volume of the solid (shell meithod)
by
MarkFL
Examine your limits of...
14:12 
greg1313
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Re: m2215b.14 Find the limiting velocity
by
karush
Where is $t$? 7627...
03:21 
karush
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Re: m2215b.14 Find the limiting velocity
by
MarkFL
$\text{14 The velocity...
03:08 
MarkFL
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Re: m2215.12 length of curve
by
karush
always learn cool tricks...
02:59 
karush
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Re: m2215.12 length of curve
by
Prove It
$\displaystyle L =...
02:59 
karush
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Re: m2215.12 length of curve
by
skeeter
$\begin{align*}\displayst...
December 6th, 2017
17:21 
karush
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Re: 243.12.7.12 plane from 3 points
by
HallsofIvy
In your first post you...
December 5th, 2017
20:32 
karush
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Re: 243.12.7.12 plane from 3 points
by
greg1313
$$ax+by+cz=d$$ ...
01:29 
karush
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Re: 243.14.7.5 Find all local extreme values
by
MarkFL
We are given: ...
December 3rd, 2017
12:32 
karush
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Re: 243.14.7.4 Find all local extreme values
by
HallsofIvy
$f(x,y)= x^2+ 14x+ y^2...
December 1st, 2017
00:43 
MarkFL
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Re: 243.13.01.19 For which path is the particle's speed constant
by
karush
no prob happens
November 30th, 2017
21:33 
tkhunny
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Re: 243.13.0113 Find the angle between the velocity and the acceleration vectors at time t=0
by
karush
Sometimes, a quick...
November 29th, 2017
17:13 
karush
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Re: 243.13.01.19 For which path is the particle's speed constant
by
MarkFL
Here, you just want to...
15:41 
karush
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Re: 243.13.01.18 motion of a particle
by
MarkFL
$\cos{(10t)}=0$...
November 28th, 2017
22:50 
karush
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Re: 243.13.01.18 motion of a particle
by
MarkFL
I would just set: ...
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