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#1 Re: Help Me ! » percentage » Yesterday 06:26:45

Hi Zeeshan 01,

As bob bundy points out, if the problem is taken word for word, then my answer is correct. On balance, I think bob bundy's answer is more likely if the phrasing is open to ambiguity. However, the problem appears to have been written in your own words -- could you post the problem as it appears on your problem sheet, unchanged?

#2 Re: Help Me ! » Need help with a puzzle. » 2017-07-20 20:02:36

Suppose Roger's age this year is
14 years ago, his age would have been
Since we are given that Roger's age is 4 less than three times a half of his age 14 years ago, then this tells us that:

Can you see where to go from here?

#3 Re: Maths Teaching Resources » LearnMathsFree - Free Maths YouTube Videos » 2017-07-18 20:10:15

In this video, we work through a double integral requiring a change in the order of integration:

The example we work through is

#4 Re: Help Me ! » percentage » 2017-07-18 00:05:32

To find
, you'd do:

Similarly, to find
, you'd do:

We're given that that is
, so that means


Zeeshan 01 wrote:

eg .  An increase of 10% is the same as multiplying the original by 1.1
and a decrease of 20% is the same as multiplying by 0.8

If you wanted to increase 20 by 10%, one way of doing that is just to do
That's because

#5 Re: Guestbook » God I hate math » 2017-07-17 19:48:47

How come?

Welcome to the forum, jenny0!

#6 Re: Maths Teaching Resources » LearnMathsFree - Free Maths YouTube Videos » 2017-07-17 00:51:43

In the latest video, we look at the following integral, and explore an interesting way of solving it:

#7 Re: Dark Discussions at Cafe Infinity » Maryam Mirzakhani passed away » 2017-07-17 00:48:47

Very sad. Some professors at my university had the privilege of having met her. CBS reported on it here.

#8 Re: Help Me ! » Help me on Vectors ... pls » 2017-07-10 01:32:57

First, compute
. We see that:

Recall that two vectors are perpendicular if their dot product (also called scalar product) is zero.

So you want to show that the dot product of
is zero, for some choice of
. Now all you have to do is try the different possibilities given and see which one gives you
when you take the dot product.

Feel free to let us know if you need more help!

#10 Re: Science HQ » Find F » 2017-07-04 05:17:13

It is variable, because its vector components each depend on

#11 Re: Science HQ » Find F » 2017-07-04 04:16:11

That tells you that the magnitude of the force is constant, but the force itself is not.

#13 Re: Help Me ! » Fraction » 2017-07-04 00:32:01

Hi Zeeshan 01,

Did you find the answer you were looking for?

#14 Re: Science HQ » Find F » 2017-07-04 00:26:51

You might like to try differentiating
, then using
This gives you
as a function of
. Is it constant or does it vary with

#21 Re: Help Me ! » Fraction » 2017-07-02 01:58:03

Zeeshan 01 wrote:

Can any one show me this fraction
And Question is how many (3÷1)in (1÷2)??

means the same thing as
. Similarly

So you want to know how many times
goes into
. That's the same as asking what
is, which is the same as
(we can change the
into a
, as long as we flip the second fraction over). But

#22 Re: Dark Discussions at Cafe Infinity » 2015 UK General Election » 2017-06-09 21:46:32

Final results:

Conservatives - 318
Labour - 262
SNP - 35
Lib Dems - 12
DUP - 10
Sinn Fein - 7
Others - 6

Result: Hung parliament. Conservatives short 8 seats of a majority.

It is understood that Theresa May will attempt to form a Conservative minority government with some sort of deal with the DUP, possibly a confidence and supply agreement.

#24 Re: Help Me ! » My daughter need some help with this » 2017-06-04 23:48:28

The natural numbers, denoted by
, are usually given as the infinite set
. Some authors take it to include the number
, and to mark this distinction, they often write this as
or the more explicit
. Authors usually make it clear what they want to mean by 'natural number'. However, I have never come across any ambiguity over the use of the word 'integer' -- denoted by
, it always describes the set
in the modern usage of the word, unless you have seen otherwise?

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