Melody

921 Questions
34315 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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858

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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 ..

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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

+118690

0

a-13>1
Right answer 'unknown name'

This a you tube clip that will show you how to solve inequations. It is very good.
Just copy and past the address into your address bar and you can watch it.

http://www.youtube.com/watch?v=OKlRsTV43oY

The presenter tell you that you have to swap the sign around if you multiply or divide by a negative number but,
There is a couple of things that the presenter, Tyler, doesn't tell you

1) If you swap sides you have to turn the sign around.
so if
5 < x
then the final answer will be
x > 5

2) if you take the reciprocal of both sides (which is probably not a method taught much anyway) then you have to turn the sign around.
so if
3/y > 4/3
then
y/3 < 3/4
which can then be simplified
y < 9/4
y < 2 and a 1/4

Melody8 dic 2013

+118690

0

andriannaneighly wrote:20134/2 *34-45+98+=????????

Hi Adrianna,
Why do you need help?
Which bit don't you understand?

Melody8 dic 2013

+118690

0

Now that is a good question. I don't know.

Maybe he didn't die and he wants to know how far he has to swim to get to the bottom of the cliff.

Maybe he is like me and just wants to work it out because it is fun!

Melody8 dic 2013

+118690

0

Root 2 ia not exactly 1.4, that is an approximation

root2 is an irrational number which means that it cannot be written exactly as a fraction or a decimal. It can't even be written exactly as a recurring decimal, the numbers after the point would just keep going for ever and would not even form a repeating pattern.

Melody7 dic 2013

+118690

0

4+1 =5 and 2+2=4 so 54? and 9-5=3 and 8-4=4 so 34?

Hi Lily,
42+12 does equal 54, you are correct

However, 98-54 does not equal 34 because 9-5 is not 3.
--------------------------------------------------------

I'd like to talk a little more about adding 2 digit numbers.
At school you probably line up 42 and 12 underneath each other so the 12 is exactly under the 42.
The 2 is under the 2 you add them and you get 4
The 1 is under the 4 you add them and you get 5
The answer is 54

But what about 58+14?
8+4=12
5+1=6
But the answer is not 612, that would be too big!
If you were doing it the school method you would do
8+4=12
put down the 2 and carry the 1
then 5+1+ 1 = 7
so 58+14 = 72

If you were doing this in your head,
you might say
58= 50+ 8
14= 10+ 4

50+10=60 (That is 5+1 with a zero after it)
8+4=12

60+12 => 60+10+2 => 72

Why don't you try to do 38+15 ?
I would love to see you answer it and I know the professor would too!

Melody7 dic 2013

+118690

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My question is y=12 and x=2 what is x*y*s?

x*y*s = 2*24*s => 48s

Hi Chen mei and Victoria,
You two sound like a couple of fun young people.
I like that!

喜陈尾及维多利亚，
你们两个听起来像几个有趣的年轻人。
我喜欢！

Hola Chen mei y Victoria,
¿Suena como un par de jóvenes.
¡Me gusta!

Melody7 dic 2013

+118690

0

y = log X
If y = 10, then what is X?

Hi Hazzer,
It would depend on what base your log is in but normally a base of 10 is implied
so your questions is

y = log ₁₀X
Substitute 10 for y and you get
10 = log ₁₀X

x=10 ¹⁰

Another way to do it is as follows

10 = log ₁₀X

10 ¹⁰ = 10 ^log₁₀X

10 ¹⁰ = 10 ^log₁₀X => X (The 10 and the log base 10 cancel each other out)

Melody7 dic 2013

+118690

0

Sorry Daniel,
You are right, it was late at night and I didn't read your question properly.
I trust the Professor has sorted it out for you now.
If you still have problems, don't hesitate to post again.
Melody.

Melody7 dic 2013

+118690

0

Hi Guest

ex. -7*sqrt3(x^2)+sqrt3(27x^2)+sqrt3(64x^2)

What you meant was
-7*The cube root of (X ²) + The cubed root of (27X ²) + The cube root of (64X ²)

Now, the cube root of something is a power of 1/3
so your question becomes

-7*(X ²) ^1/3 + (27X ²) ^1/3 + (64X ²) ^1/3

= -7*(X ²) ^1/3 + (27*X ²) ^1/3 + (64*X ²) ^1/3

for your next step or your next 2 steps depending on how quickly you decide to do it you need to use 2 indice properties.
I'll give you examples which you can use to answer your own question

(a*b) ⁶ = a ⁶ * b ⁶
and

(a ^m) ⁿ = a ^(m*n)

After you do this you will have 3 like terms (which are to be added)
When you add them you will get 0.

See if you can do the last bits by yourself. If you get stuck make sure you post again so that I, or someone else can help you some more.

Your inital post was very vague, it is lucky that our guest and the Professor, quizzed you about it. When you responded, you made it very clear what your question was.
And, that is why you now have an answer.
I am a university trained, fully qualified and experienced mathematic teacher (so that makes at least 2 of us who can answer your questions).
There are other people on this forum who are also very capable.
Melody.

Melody7 dic 2013

+118690

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find all real roots by using quadratic formulae. 2x^2-9x=1

Hi Daniel,
You can either use completing the square method or
you can take 1 from both sides and then use the quadratic formula.
If you get stuck you can post again, but try to work it out yourself first.
Melody.

Melody7 dic 2013