Melody

921 Questions
34316 Answers

+1

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+118735

Mathigon website

I just discovered a site called mathigon

https://mathigon.org/dashboard
read more ..

Melody Apr 2, 2022

-8

612

1

+118735

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. read more ..

Melody Mar 16, 2022

-2

8

1481

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+118735

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 read more ..

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Melody Mar 15, 2022

-3

873

3

+118735

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

off-topic

Melody Mar 13, 2022

-4

850

3

+118735

WELCOME BACK CPHILL !

Melody Feb 11, 2022

-5

721

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+118735

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. read more ..

Melody Feb 1, 2022

-7

888

11

+118735

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 read more ..

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Melody Jan 9, 2022

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1

999

3

+118735

HAPPY BIRTHDAY CHRIS!

Melody Dec 20, 2021

+5

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5577

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+118735

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 read more ..

off-topic

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Melody Nov 4, 2021

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1096

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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

off-topic

Melody Oct 29, 2021

+118735

0

Heueka just wrtote some electricity formulas with LaTex - a few new symbols I think. Thanks Heureka.

http://web2.0calc.com/questions/if-voltage-source-is-12-resistance-is-6800-and-voltage-1-is-8-what-is-r2#r1

MelodyJan 9, 2015

+118735

0

Thank you Heureka

I am going to reference this from the LaTex page too. Thanks again :)

MelodyJan 9, 2015

+118735

+5

$${\frac{{\mathtt{9\,999}}}{{\mathtt{60}}}} = {\frac{{\mathtt{3\,333}}}{{\mathtt{20}}}} = {\mathtt{166.65}}$$

166.65 hours

MelodyJan 9, 2015

+118735

+5

-800x10^-3

=-800. x 10^-3 There is an invisable decimal point after the 800

Now the index (of 10) is negative so this is going to be a little number.

Move the decimal point 3 places in the direction to make the number smaller.

=-.8 I jumped the point over 0, over 0, and over 8 that is the 3 jumps.

now put a zero infront of the point so that you can see it easily.

= -0.8

MelodyJan 9, 2015

+118735

+10

Thank you Chris for discovering this for us

This Wikipaedia site that Chris has referred us too is interesting.

http://www.digplanet.com/wiki/Degenerate_conic

Unlike Chris I like to put my feet up and watch video clips. There are tabs at the the top and one is for youtube clips.

I just watched the first one and really liked it.

--------------------------------------------

Actually I just found another simple page one conics.

My knowledge of conics was worse than Chris's in the first place so this is quite enlightening.

http://www.sparknotes.com/math/precalc/conicsections/section1.rhtml

This is what I have learned:

The general form of a conic is

$$Ax^2+Bxy+Cy^2+Dx+Ey+F=0\\

Now if B=0 we have\\

Ax^2+Cy^2+Dx+Ey+F=0\\

If A=C it is a circle\\

If A\ne C \;\; \mbox{BUT A and C have the same sign then it is an ellipse}\\

If A\ne C \;\; \mbox{AND A and C have different signs then it is an hyperbola}\\$$

---------------------------------------------------------

Ours has an xy term so B is not equal to zero - I do not know what that makes it.

It is a degenerate conic that is for sure but i am not sure which one.

I would really like more imput from other mathematicians :)

MelodyJan 9, 2015

+118735

+5

put the numbers in order - then the MIDDLE one is the MEDIAN.

Here is a site for you

http://www.metric-conversions.org/length/meters-to-feet.htm

MelodyJan 9, 2015

+118735

+5

cos B cannot equal 42.25 because cosine must be between -1 and +1

MelodyJan 9, 2015

+118735

+5

$$\frac{-20}{15}$$

Divide top and bottom by 5

$$=\frac{-4}{3}$$

$$=-(\frac{3}{3}+\frac{1}{3})$$

$$=-(1+\frac{1}{3})$$

$$=-1\frac{1}{3}$$

MelodyJan 9, 2015

+118735

+5

p-1/-3=-4

p+(-1/-3)=-4

a neg divided by a neg = a pos

so this is better written as

p+(1/3)=-4

subtract 1/3 from both sides

p= -4-(1/3)

p=-(4+1/3)

$$p=-4\frac{1}{3}$$

MelodyJan 9, 2015

+118735

+5

You cannot solve for anything - there is no equal sign

MelodyJan 9, 2015