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#102 Re: Help Me ! » The first 3 decimals of this number » 2017-01-04 05:32:53

Mario23 wrote:

So I should prove that


is independent of n?
EDIT:That's the only thing I can't prove so I could use a hand smile

It should be7n*{1/(280n)-1/(8*140^2*n^2)}=1/(40)-7/(8*140^2*n)

#103 Re: Help Me ! » Logical question s » 2016-12-30 00:02:17

bobbym wrote:

Question 5) Anything wrong with trying all 4 and a bit of algebra.

Better try with maximum 3 digit number and minimum 2 digit number.

#104 Re: Help Me ! » train accelerating » 2016-12-29 22:35:11

iamaditya wrote:

Hi. I Also agree with thickhead's answer. I solved like this:





v2=0 m/s (Stopping at rest)
u2= v m/s
a2= 3a m/s²

v²=u²+2as
⇒s=(v²-u²)/2a
⇒s2=(v2²-u2²)/2a2
⇒s2=(-u2²)/2a2
⇒s2=(-v²)/6a

v=u+at
⇒v2=u2+a2t2
⇒(v2-u2)/a2=t2
⇒-u2/a2=t2
⇒-v/3a=t2

Avg. Speed=Total distance/Total time
=(s1+s2)/(t1+t2)
=v/2

v/2=√(s1+s2)
⇒v/2=v/√(3a)
⇒2=√(3a)
⇒4=3a
⇒a=4/3 m/s²

v2=0 m/s (Stopping at rest)
u2= v m/s
a2=- 3a m/s²

v²=u²+2as
⇒s=(v²-u²)/2a
⇒s2=(v2²-u2²)/2a2
⇒s2=(-u2²)/2a2
⇒s2=(v²)/6a
s1+s2=v²/2a+v²/6a=2v²/3a

#106 Re: Help Me ! » Archer's Arrow Enigma » 2016-12-29 00:05:54

Mathegocart wrote:

The (i.e, vertical)perpendicular distance between both opposing windows is 12 ft.
-Mathe

I like clarity on this point.Is it not horizontal distance between opposing windows?And what is the value of 'g' in fps units? I vaguely remember it as 32 ft/sec^2. Is it right? I am used to S.I. units.

#108 Re: Help Me ! » Closed form for generating functions » 2016-12-25 17:40:51

It comes readily from the series expansion of log(1+x) and log(1-x)

#109 Re: Help Me ! » How do u determine r, b, amt? » 2016-12-25 16:05:44

jxharmon wrote:

I think it is this: I keep 2nd guessing myself!

RATE= 8
BASE=25
AMOUNT=% OF STUDENTS RECEIVING A'S
????

RATE=32
BASE=25
AMOUNT=NUMBER  OF STUDENTS RECEIVING A'S=8
I corrected the mistake in rate.

#114 Re: Help Me ! » projectile » 2016-12-18 18:18:52

For the new problem get u in terms of gt and calculate s1 and s2. Simple. I am afraid I should not reveal anything more.

#115 Re: Help Me ! » projectile » 2016-12-18 05:03:15

You are on correct path. eliminate t from the 2 equations.

#116 Re: Help Me ! » How to solve these equations » 2016-12-17 22:08:38

mr.wong wrote:

Hi  zetafunc ,

Will  you  please  give  an  example  ? 

Hi  thickhead ,

Once  you  have  got  a  valid  pair  of  i  and  j , then  you  may  add 
n * 182 * 165  to  both  sides  of  182 * i   and  165 * j  and  obtain  a  bunch  of  i  and  j   as  you  had  stated  in  # 3 . While  to  express  a  certain  prime   as   a * 17 +  b * 5   may  need  trial  and  error .

That trial and error is quite easy because of 5.e.g. 173 You have to find a multiple of 17 ending with 3 or 8 i.e 68+105 or 153+20  but the resulting i and j you have to check for the condition.

#117 Re: This is Cool » New radical formula? » 2016-12-16 18:12:27

Hi evene,
Where are my bonus points?

#118 Re: Help Me ! » simplify » 2016-12-16 14:55:29

hi Monox D. I-Fly,
It was just for fun.I have neither  objection ,nor any authority nor any intention to do so. My contention was it may not benefit the one who asked the question. I too have responded to queries 2 to 3 years back when the topic was found interesting.

#119 Re: Help Me ! » simplify » 2016-12-15 21:16:00

Hi Monox,
Digging up 10 year old grave?

#121 Re: Help Me ! » How to solve these equations » 2016-12-13 21:21:55

mr.wong,
I goofed about the restraints again.On close observation I find i is relatively prime with 165 only ,not necessarily with 182. So
182*{-97*929+547*165}=142 and 165*{-107*929+547*182}=151
182*{-97*929+548*165}=307and 165*{-107*929+548*182}=333
182*{-97*929+549*165}=472 and 165*{-107*929+549*182}=515
182*{-97*929+550*165}=637 and 165*{-107*929+550*182}=697
182*{-97*929+551*165}=802 and 165*{-107*929+551*182}=879
All these are valid pairs of i and j.

#122 Re: Help Me ! » How to solve these equations » 2016-12-13 17:44:23

When I got this  182*{-97*929}-165*{-107*929}=929 I was not happy since i and j were negative but since your condition was on integer I allowed it.However it is possible to add and subtract packets of 182*165 as many as you like to make them positive keeping eye on relatively prime condition. I added and subtracted 552(547 is sufficient to make them positive but relatively prime condition could not be met) packets to each term.Thus 182*{-97*929+552*165}=967 and 165*{-107*929+552*182}=1061. as I told you I relied on only (1) and (2) in #3 but more such relations could be found.

#123 Re: Help Me ! » How to solve these equations » 2016-12-12 20:40:43

(5)182*{967}-165*{1061}=929
Is it o.k.?

#124 Re: Help Me ! » How to solve these equations » 2016-12-12 18:26:21

mr.wong,
I am very sorry,I had not read the problem carefully. 182 and 165 are relatively prime but I had overlooked that for i and j. I was wondering why there are only some specific numbers on R.H.S.As a matter of fact I had not gone through your earlier thread on prime numbers.

#125 Re: Help Me ! » Algebra Problems » 2016-12-12 03:17:23

What is the outcome for (1)?

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