Melody

921 Questions
34315 Answers

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1731

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+118691

Mathigon website

I just discovered a site called mathigon

https://mathigon.org/dashboard
और पढ़ें ..

Melody 2 Apr 2022

-10

596

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+118691

Reporting problems.

There are a number of people having problems at the moment.
If you lodge an error can you please give all relevant information that you can think of.
Where you are in the world - the city or the country - is often very important information. और पढ़ें ..

Melody 16 Mar 2022

-4

1404

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+118691

How to make an empty rectangle in Latex

I just worked out how to make an empty box of various horizonal size easily in LaTex.
This is not a recommended method, but other methods that I have tried here have not worked.
This coding is really simple. Just put letters inside और पढ़ें ..

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Melody 15 Mar 2022

-5

859

3

+118691

HAPPY ANNIVERSARY CHRIS! (CPhill)

I just realized that you became a member here exactly 8 years ago today!

It has been great to have you here all that time

और पढ़ें ..

विषय से परेे

Melody 13 Mar 2022

-6

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+118691

WELCOME BACK CPHILL !

Melody 11 Feb 2022

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Very interesting question. No high level maths required.

This question was posted a couple of days ago.
https://web2.0calc.com/questions/geometry_73561

I think it is really interesting. It looks much more difficult than it really needs to be. और पढ़ें ..

Melody 1 Feb 2022

-8

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Members have a better experience. Their questions get more attention.

Almost everyone is posting as a guest.
If you post as a member your questions will have a far greater chance of a timely and helpful response.
If you are a genuine learner and interact with us, you will become known and answerers will do और पढ़ें ..

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Melody 9 Jan 2022

-8

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HAPPY BIRTHDAY CHRIS!

और पढ़ें ..

Melody 20 Des 2021

+4

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Some guidelines for question askers.

Please note:
1) Ask only one question per post.
2) When asking a question talk about what you have tried for yourself. Then people will take you more seriously and will be more able and willing to help.
3) If you get an answer और पढ़ें ..

विषय से परेे

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Melody 4 Nov 2021

-10

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Remeniscing - a little historical humour.

I just found this old post that some of you, who have been around for a while, might find amusing.

https://web2.0calc.com/questions/look-at-the-new-leader-board

विषय से परेे

Melody 29 Okt 2021

+118691

+27

*
Sorry guys, not all questions are answered to this point. I've run out of time.
There are 5 posts that I seriously want to return to, I might not get to all but i will try.

There were lots of great answers given by helpers today. Otherwise there would be even more posts unanswered. Thank you so much.
Helpers today were
Sudenpur, Bagelfood, mathnut 8, unicornrainbow, 2548, MissLuna, Zamarronics, Dee, and a couple by 'guests'
oh, and there was a great little sketch by NoTrees.

Good night all.

Melody.

Melody14 Jan 2014

+118691

0

RSA:
(1/192) = k mod 7
whats k?

I ran it through a calculator and the answer is 5.
I am not very experienced with modular arithmetic but
I assume that this is because

First I will rearrange the equation
(1/192) = k mod 7
1 = 192k mod7
192k = 1 mod7 and this means that
192k divided by 7 will have a remainder of 1

now
192*5 divided by 7 = 960 divided by 7 = 137 remainder 1
with modular arithmetic it is the remainder that is important.
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I may return to this question later, like i said, I am not very familiar with modular arithmetic.

Melody14 Jan 2014

+118691

0

Are you a little bit dyslexic dee? 11 x 15 = 165
so the first 3 digits are 165 not 156

Now Scott,
your question is ambiguous.
In Australia and the UK I think, a billion is a milion million, that is 1,000,000,000,000 or 10 ¹²
but in the US a billion is a thousand million, that is 1,000,000,000 which is 10 ⁹

Melody14 Jan 2014

+118691

0

NOTREES:
http://i2.kym-cdn.com/entries/icons/original/000/007/423/untitle.JPG
NO
copy and paste link

Great sketch - Did you do it yourself?

Melody14 Jan 2014

+118691

0

SUSHILA GARG:
Use a computer algebra system to calculate the total length of the 5 petal rose with r=cos5t

What does r and t stand for?

Melody14 Jan 2014

+118691

0

regi:
nilai maksimum f(x,y)=4x+12y pada x+2y<8;3x+2y<12;x>0;y>0 adalah

Hi Regi
This is in Indonesian
English translation is
The maximum value of f (x, y) = 4x +12 y on x +2 y <8; 3x +2 y <12; x> 0; y> 0 is
I am not sure what this means. I think that it means, find the maximum value of 4x+12y given that the region is bounded by all the inequalities.
I graphed the restricted area and this is what I got.
14014 Indonesian question.JPG

I check the value of 4x+12y on each of the points of intersection and the biggest value was 48 at (0,4)
I think the answer is 48.
I have asked some mathematician friends to comment on this. If I get better/more information. I will repost.
----------------------------------------------------------------------------------------------
Hi Regi
Ini adalah dalam bahasa Indonesia
Terjemahan bahasa Inggris
Nilai maksimum dari f (x, y) = 4x +12 y pada x +2 y <8; 3x +2 y <12; x> 0, y> 0 adalah
Saya tidak yakin apa artinya ini. Saya berpikir bahwa itu berarti, menemukan nilai maksimum 4x +12 y mengingat bahwa daerah tersebut berbatasan dengan semua ketidakadilan.
Aku digambarkan area terbatas dan ini adalah apa yang saya dapatkan.
[attachment = 0] 14014 Indonesia question.JPG [/ attachment]

Saya memeriksa nilai dari 4x +12 y pada setiap titik persimpangan dan nilai terbesar adalah 48 pada (0,4)
Saya kira jawabannya adalah 48.
Saya telah meminta beberapa teman matematika untuk mengomentari ini. Jika saya mendapatkan informasi yang lebih baik / lebih. Saya akan mengumumkan kembali.

Melody14 Jan 2014

+118691

0

jac:
given function y= 3sin(2pix) find amplitude and period

A more general equation would be

Consider y=sin(x)
This is the most basic of sine funtions.
It has an amplitude of 1 and a wavelength of 2pi radians (360degrees)
Amplitude is the distance from the centre of the wave to the highest point (resting point to peak)
Wavelength (the symbol is the upside down y thing called Lambda) is the distance the wave travels in one cycle.

Now look at a slightly more complicated one
y=Asin(Bx)
This time the amplitude is A
and the period is 2pi / |B|

Do you need more than this? Have a look at this site. You can play with A and B and see what happens.

https://www.desmos.com/calculator/nzql7i9y90
I've set the sliders for A=1 and B=1 you can move them to see what happens if A and B have different values.

Now, you should be able to tell me, what it the amplitude and the period of y = 3sin(2pix)

Melody14 Jan 2014

+118691

0

Gibbs.ian:
A card is selected at random form a standard deck of 52. What is the probability of selecting a diamond?

There are 4 suites. There is the same number of cards for each suite.

So P(diamond)=1/4
or
there are 13 diamonds and 52cards
P(diamond) = 13/52 = 1/4

Melody14 Jan 2014

+118691

0

davidashworth7:
[13] Use logs to derive the linear form (i.e. an equation that would allow you to plot a straight-line
graph) of the following equations:

n = K M^a
I = Io.e^-kt
m = k [c]^1/n

These are some practice questions I was given and for the life of me can't tell what it wants me to do with them any help? dont need to answer them just a general idea of how to tackle them?

I really don't know what your teacher is after. Do you know which of the pronumerals are constants and which are variables? (This makes a big difference to any possible solution)

If the second one is meant to be
l = ln [e ^-kt]
then this would simplify to
l = (-kt) ln e
l = -kt
If k is a constant and t and l are variables then this is a linear equation.

If you have more information please post it.
OR
If you get the answers please post them so i can see what your teacher is talking about.
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I am sorry that I can't be more helpful.
There are a couple of sites that I often refer people to regarding logs, maybe you will find one of them helpful.
http://en.wikipedia.org/wiki/List_of_logarithmic_identities
http://www.mathsisfun.com/algebra/logarithms.html

Melody14 Jan 2014

+118691

0

What have you done towards solving this yourself?

Melody14 Jan 2014