Melody

921 Questions
34316 Answers

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Mathigon website

I just discovered a site called mathigon

https://mathigon.org/dashboard
lee mas ..

Melody 2 abr 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. lee mas ..

Melody 16 mar 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 lee mas ..

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Melody 15 mar 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

Fuera tema

Melody 13 mar 2022

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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. lee mas ..

Melody 1 feb 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 lee mas ..

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Melody 9 ene 2022

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HAPPY BIRTHDAY CHRIS!

Melody 20 dic 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 lee mas ..

Fuera tema

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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

Fuera tema

Melody 29 oct 2021

+118735

+5

Thanks Alan that makes sense.

How did you work out my expression?

Melody19 abr 2015

+118735

+13

This is what I have come up with. :/ [no guarantees that it is correct though]

Where on Earth are you digging these questions up from Mellie. :))

Now I have to work out how to calculate this without doing every bit separately.

Got any ideas Alan? Do you know how to get the web2 calc to do the numerator?

$$\displaystyle\sum_{x=1}^{40}\left(\frac{39!}{(40-x)!}\times(52-x)!\right)\div 52!$$

Melody19 abr 2015

+118735

0

Who would like to add their birthday to the list ?

Melody18 abr 2015

+118735

+5

how do I solve for x in, sin2x=2sinx when in the intervals of [0,2pi)?

$$\\2sinxcosx=2sinx\\
cosx=1\\
x=0$$

Melody18 abr 2015

+118735

+5

what is the question?

Melody18 abr 2015

+118735

+5

http://www.binaryhexconverter.com/hex-to-decimal-converter

Melody18 abr 2015

+118735

+14

@@ End of Day Wrap Sat 18/4/15 Sydney, Australia Time 9:40pm ♪ ♫

Good evening

Great answers today from Alan, Trincent, Zacismyname, Badinage, CPhill, Brittany and Zegroes. Thank you :)

Rosala is back. She has been away at a wedding the second one in about a month. I think she only came home to change her clothes Anyway, she is back home and back with us now. Welcome back Rosala.

Interest posts:

FTJ means "For the Juniors"

1) Cute pic Thanks anon

2) Forum fun Thanks Badinage and BrittanyJ

3) I am not really sure that these answers helped Thanks Zegroes and CPhill

4) Simplifying a complex number Melody

5) What is the e on the calculator? FTJ Melody

6) Graphing calcs and factorising cubics Thanks Badinage, Melody and Alan

7) Bernoulli trial - confidence interval Not answered - I tried and failed

8) Solving an inequality Thanks Alan and Melody

♫♪ ♪ ♫ ♬ ♬ MELODY ♬ ♬ ♫♪ ♪ ♫

Melody18 abr 2015

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0

Sun 19/4/15

FTJ means "For the Juniors"

1) Today's Fun thread Thanks BrittanyJ

2) Warm Fuzzy post :) Thanks anon

3) Probability 1. Want to see the hard way just ask me. Thanks Alan and Melody

4) Probability 2 (number theory?) No answer yet

5) Probability 3 Coin tossing - I made a discovery here Thanks Melody and Alan

6) Probability 4 Expected value and others No answer yet

7) Probability 5 I really like this answer. Thanks CPhill

8) Probability 6, nongon I only did part A Melody

9) Expected values Thanks Alan

10) Trig and factorising Thanks Melody and Alan

11) Expected values Thanks Alan

12) Expected values 2 Not answered yet

13) Finding Total length FTJ Thanks Mellie

14) Function question Thanks Alan and Melody

15) Great geometry / integration question Thanks Melody and CPhill

16) Power of infinity - it is tricky Thanks Geno

♫♪ ♪ ♫ ♬ ♬ MELODY ♬ ♬ ♫♪ ♪ ♫

Melody18 abr 2015

+118735

0

Thanks Badinage :)

Melody18 abr 2015

+118735

+10

I am going to try and do it by hand

$$\\(x-2)^{x-3}<(x-2)^{5-x}\\\\
(x-3)log(x-2)<(5-x)log(x-2)\\\\
(x-3)log(x-2)-(5-x)log(x-2)<0\\\\
(x-3-5+x)log(x-2)<0\\\\
(2x-8)log(x-2)<0\\\\
(x-4)log(x-2)<0$$

this will be true if one of the factors is negative and the other is positive.

log(x-2)>0 when x-2>1 that is when x>3

x-4>0 when x>4

so

If x4 then both are negative.

BUT the goldilocks moment comes

when x is between 3 and 4 because then x-4 is neg and log(x-2) is positive

so

This will be true when 3<x<4

Melody18 abr 2015