Xenon Maths Help Thread!

Original post by _Xenon_

I need help with Maths and I can only ask here on The Student Room for help/support. I didn't want to annoy people by making threads daily so should I just ask in one thread (like this) or do you not mind if I make loads of threads with loads of maths questions?

It's fine if you keep all your questions in this thread. Others have done this in the past.

Reply 3

OP

Original post by notnek

It's fine if you keep all your questions in this thread. Others have done this in the past.

Oh OK, thank you and I can just tag you in the posts so you'll know when I have a new question. :smile:

Original post by notnek

I'll give you a similar easier question:

A bag of balls contains red and blue balls as well as other colours. 1/2 of the balls are red and 1/4 are blue. How many are not red or blue?

Answer : 1/2 + 1/4 = 3/4

So 3/4 of the balls are either red or blue.

1 - 3/4 = 1/4

So 1/4 of the balls are not red or blue.

Try and do a similar thing for this question. Post your working if you get stuck.

Thanks I'll have a go at it now.

Reply 4

Zacken

22

Original post by _Xenon_

Oh OK, thank you and I can just tag you in the posts so you'll know when I have a new question. :smile:

Just post in the thread and whoever is free will help.

(Do note that if you want to post a new thread asking a question, that's fine as well, just make sure you don't post a new thread and ask the same question in here).

Reply 5

Notnek

Original post by _Xenon_

Oh OK, thank you and I can just tag you in the posts so you'll know when I have a new question. :smile:

No need. If I'm online then I will look at your thread and respond to your question if I have time.

Reply 6

OP

Original post by Zacken

Just post in the thread and whoever is free will help.

(Do note that if you want to post a new thread asking a question, that's fine as well, just make sure you don't post a new thread and ask the same question in here).

Yep thanks.

Original post by notnek

No need. If I'm online then I will look at your thread and respond to your question if I have time.

OK thanks, hopefully I still get fast responses. :-)

Reply 7

OP

FUNCTIONS is confusing!!!!

Reply 8

Math12345

14

Any specific question?

Reply 9

Notnek

Original post by _Xenon_

FUNCTIONS is confusing!!!!

Which specific part? Post an example question.

Reply 10

thefatone

6

Original post by _Xenon_

FUNCTIONS is confusing!!!!

Like transforming graphs?

Reply 11

TheConfusedMedic

Original post by _Xenon_

FUNCTIONS is confusing!!!!

Do you mean things such as:
f(x+a) translates graph horizontally by -a
?

Reply 12

OP

Original post by notnek

Which specific part? Post an example question.

Original post by thefatone

Like transforming graphs?

Original post by surina16

Do you mean things such as:
f(x+a) translates graph horizontally by -a
?

OK sorry about thag, I'll post one in a couple of minutes

OP

Functions

Original post by _Xenon_

Functions

Do you understand how to do

f(a)

? That is, if you have some function

f(x) = 2x

(let's say) then when you want to evaluate

f(2)

, you just need to replace anywhere you see an "x" with a "2". So:

f(2) = 2(2) = 4

.

In a more complicated example;

f(x) = \frac{2x}{x+4}

, what is

f(6)

? You just need to replace the x's with a 6; that is:

f(6) = \frac{2(6)}{6+4} = \frac{12}{10}

.

So, in your case, what is

f(7.5)

?

Reply 15

OP

3/(2*7.5+5)

= 3/(15+5)

= 3/20

= 0.15

Not sure but if it is right what about question which say which domain should be excluded from x or something like that anyway, thanks.

Reply 16

Zacken

22

Original post by _Xenon_

3/(2*7.5+5)

= 3/(15+5)

= 3/20

= 0.15

Not sure but if it is right what about question which say which domain should be excluded from x or something like that anyway, thanks.

Yeah, that's fine.

Can you divide by 0, by the way? Just wondering.

Reply 17

phat-chewbacca

16

Original post by _Xenon_

Functions

What book are these questions from? Have you got pdfs of A*-B grade topics?

Reply 18

OP