Melody

921 Questions
34315 Answers

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Mathigon website

I just discovered a site called mathigon

https://mathigon.org/dashboard
lire plus ..

Melody 2 avr. 2022

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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. lire plus ..

Melody 16 mars 2022

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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 lire plus ..

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Melody 15 mars 2022

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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

Hors sujet

Melody 13 mars 2022

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WELCOME BACK CPHILL !

Melody 11 févr. 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. lire plus ..

Melody 1 févr. 2022

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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 lire plus ..

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Melody 9 janv. 2022

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HAPPY BIRTHDAY CHRIS!

Melody 20 déc. 2021

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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 lire plus ..

Hors sujet

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Melody 4 nov. 2021

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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

Hors sujet

Melody 29 oct. 2021

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That is the same only to 1 significant figure.
cheers.

Melody11 oct. 2013

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First I googled the density of fresh water at 20 degrees celcius and got 998.21Kg/cubic metre
I changed the Kg to grams and the 1cubic metre to cubic cm and did the division.
If the density of the material is greater than water it will sink, if less then it will float.
that's my logic anyway.

get back to me if you want more help or to check you answer against mine.

Melody11 oct. 2013

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You are very welcome
did you get 3645 / (9^3) = 0.499 g/cm ³ (to 3 significant figures)

Melody11 oct. 2013

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I think you mean inverse sin. Sometimes called arcsin
NOTE: inverse sin is totally different from (sin x) ^-1 which means 1/sinx

sin 30 ^o = 1/2 = 0.5
therefore
arcsin 0.5 = 30 ^o
or it might be written as
sin ^-10.5 = 30degrees

on a calc you press
asin 0.5=
or
inv sin 0.5 =

You just have to be very careful that the calculator is displaying degrees rather than radians. This is a common error.

Melody11 oct. 2013

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yes, that is right.

Melody11 oct. 2013

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Density is mass divided by volume, does that help?

Melody11 oct. 2013

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Well,
How many beats in 1 minute?
How many beats in 2 minute?
How many beats in 3 minute?
How many beats in 10 minute?

How many minutes in an hour?
Do you get where I am going here?

Melody11 oct. 2013

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first you should recognise that these are all lines.

one solution means that the lines will cross each other
no solutions mean that they are parallel so the ?? will be the same
infinite solutions mean that they are the same line,

I hope this is enough to get you started.

Melody11 oct. 2013

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Remember that if the quadratic formula does not make sense
I mean the discriminate b ²-4ac < 0 then there are no solutions.

Melody11 oct. 2013

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Sorry, this question does not make sense.

Melody11 oct. 2013