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

-10

590

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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

-5

854

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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

+118677

+1

Don't you have a calculator?

Melody30 sept. 2013

+118677

+1

Do you mean (square root of 3) * -27? The answer is irrational but approximately -46.76
or
do you mean square root of (3*-27) ? This is a nonsense question because negative number can't have square roots.

Melody30 sept. 2013

+118677

+1

Your question does not make sense.

Melody30 sept. 2013

+118677

+1

The first one because when you times them together you get a real number.
(-10 + 3i) (-10-3i) = 100 + 9 = 109

Melody30 sept. 2013

+118677

+1

Multiply both sides by 2*(x-2)*(x+6) this will get rid of all the fractions

You get 2(x+6) + 6(x-2) = x^2 +6x -2x -12

2x+12+6x-12 = x^2 + 4x - 12

8x = x^2 +4x - 12

4x = x^2 -12

0 = x^2 - 4x -12

0 = (x+2)*(x-6)

x=-2 or x=6

If you need me to explain some of these steps in more detail just ask.

Melody30 sept. 2013

+118677

+1

root 2 is an irrational number. 2.2360679775 is still an approximation.

Melody30 sept. 2013

+118677

+1

Sorry mom, this question doesn't really make sense.
Is e a variable or is it the irrational number e ( approx 2.718)
does your point indicate multiply or a power?
Maybe you could clarify this question.

Melody30 sept. 2013

+118677

+1

4% is $46 so
1% is $46/4 = $11.50 so
5.5% is $11.50*5.5 = $63.25

Melody30 sept. 2013

+118677

+1

ok, I got 41.

Your calc might be a bit different from mine. I am using an older CASIO.
I just enter 'shift' then 'sin' to get sine-1 and then I just entered the rest as shown.
Make double sure that your calculator is in degrees mode - it might be set to radians.
If it still won't work tell me what kind of calc you are using and I may be able to help more.

Melody29 sept. 2013

+118677

+1

I did this more by trial and error than by 'real' maths.
ax^2+c>=0

x^2 is always greater or equal to 0
If a is positive then ax^2 is 0 or positive
If c is zero or positive then the answer has to be greater or equal to 0.
If there is only one correct answer then it has to be

a>0 and c>=0

Melody29 sept. 2013