Melody

921 Questions
34315 Answers

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Mathigon website

I just discovered a site called mathigon

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

Melody Apr 2, 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. read more ..

Melody Mar 16, 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 read more ..

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Melody Mar 15, 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

off-topic

Melody Mar 13, 2022

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WELCOME BACK CPHILL !

Melody Feb 11, 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. read more ..

Melody Feb 1, 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 read more ..

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Melody Jan 9, 2022

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HAPPY BIRTHDAY CHRIS!

Melody Dec 20, 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 read more ..

off-topic

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Melody Nov 4, 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

off-topic

Melody Oct 29, 2021

+118725

0

what is -3-2?

think of it like this
It is very cold
-3 degrees celcius
it gets colder by 2 degrees
that is -3-2=
what is the temperature now?

MelodyNov 25, 2013

+118725

0

Determine the angle when the adjacent measurement is 4.870 in and the opposite angle is 3.900 in

Your question doesn't make sense.
I could guess what you were talking about but there would be more than one 'guess' involved.

MelodyNov 25, 2013

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0

First you need to expand the second bracket.
And this is the long version of how it is done.

− (x − 6y + 3z)

= -1 * (x − 6y + 3z)

= -x + 6y - 3z

MelodyNov 25, 2013

+118725

0

First you need to expand the second bracket.
And this is the long version of how it is done.

− (x − 6y + 3z)

= -1 * (x − 6y + 3z)

= -x + 6y - 3z

MelodyNov 25, 2013

+118725

0

okay, I've got a much better answer

find the smallest positive integer b which satisfies 3^56=b(mod7)

3^56 = 3^(54+2) = 3^54 * 3^2 = (3^6)^9 * 9

3^6 = 729
729/7=104 remainder 1 = 1 mod 7
9 = 2 mod 7
1 mod 7 * 2 mod 7 = 2 mod 7

b=2

MelodyNov 25, 2013

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3^{56} = 523 347 633 027 360 537 213 511 521

523 347 633 027 360 537 213 511 521 / 7 = 74 763 947 575 337 219 601 930 217 with remainder 2

So find the smallest positive integer b which satisfies 3^56=b(mod7)

b=2

I don't think there can be any other answer, assuming I copied the number down right and did the division correctly (I did it by hand).
I had help from another forum just to get 3^56. My calculator couldn't handle it.
There might be another way to do this but I don't know it. If I get any other info I will pass it on to you.

MelodyNov 25, 2013

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You will move the length of the circumference of the wheel

C = 2*pi*r

You can do the rest.

MelodyNov 24, 2013

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0

4x 5 + 3 2 = 2x

You may be right Nod but maybe Danielle meant

4x^5 + 3^2 = 2x (The carrot means to the power of )

4x^5 - 2x +9 = 0

Maybe you were right Nod, mine isn't very freindly.

MelodyNov 24, 2013

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0

simplify f^3+f^2+17+8f^2-7f-2

= f^3 + f^2 + 8f^2 - 7f +17 -2

= f^3 + 9f^2 - 7f +15

just the same as Nod told you. But this is where you need to stop.

Simplify in this context means take out any brackets and collect like terms.
definitely do not put any brackets in when you simplify something like this.
If the aim of the question was to put brackets in, you would have been asked to factorise. (spelt with a z in USA I believe)

MelodyNov 24, 2013

+118725

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Why is 0.2 times 0.3 0.06?

You need to draw the pictures that I describe in order to understand what i am saying.

When you are multiplying numbers less than 1 you are best to think of the times sign as 'of'
for instance

1/2 * 1/2 = 1/2 of 1/2
And , if you have a half a cake and you eat half of it, then you will be eating 1/4 of the original cake. Draw a picture to see what I mean
1/2 *1/2 = 1/4
since 1/2=0.5 and 1/4=0.25 it follows that
0.5 * 0.5 = 0.25
I think for most people it is easier to think in fractions though.
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draw a long rectangular cake and break it into 10 pieces. each of those pieces is 1 tenth of the cake.
Now, you will need to split or imagine each of those 10 pieces split into 10 pieces to make a total of 10*10=100 pieces. Each tiny piece will be 1 hundreth of the cake.
Very lightly shade 3 tenths (0.3) of the cake. that's how much cake you started with. The rest is already gone. You have also shaded 30 hundredths (0.30) of the cake because 3/10=30/100

Yours question is 0.2 times 0.3 (0.2 of 0.3)
0.2 is 2/10 so you want

2/10 of the 30 tiny pieces of a cake that you have
1 tenth of 30 is 3
so 2/10 of 30 is 6
so the answer is 6 pieces of cake
but each piece is 1 hundreth of the original cake
so the answer must be 6 hundredths of the original cake
6 hundredths = 0.06

I hope that helps.

MelodyNov 24, 2013