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Current Year 13 Thread (2013/14) - Mark I

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Original post by L'Evil Fish
S3?!


yeah for afm lol
Original post by keromedic
??
Ah cool, so you've cut back on the STEP Qs a bit.

well I was generally doing one a day so not really
Original post by Robbie242
yeah for afm lol

well I was generally doing one a day so not really

Ah, thought you had gone up to 2 a day, 3 on weekends.
A2 mathematicians help me with this ? I'm really really stuck on it!
Find the inverse function of f(x) = x^2(4-x) and tell me how you do it please ? I'm up to the bit where it's x= y^2(4-y) :smile:








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Original post by krishkmistry
A2 mathematicians help me with this ? I'm really really stuck on it!
Find the inverse function of f(x) = x^2(4-x) and tell me how you do it please ? I'm up to the bit where it's x= y^2(4-y) :smile:
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Where did you get that question from? I can't see an easy way to do it tbh. :no:
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Avatar for Qari
Qari
20
Original post by krishkmistry
A2 mathematicians help me with this ? I'm really really stuck on it!
Find the inverse function of f(x) = x^2(4-x) and tell me how you do it please ? I'm up to the bit where it's x= y^2(4-y) :smile:








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Make y the subject again

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Original post by Qari
Make y the subject again

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I don't know how to!!!


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Original post by usycool1
Where did you get that question from? I can't see an easy way to do it tbh. :no:


ImageUploadedByStudent Room1388172228.944963.jpg
Part (iv)


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Original post by krishkmistry


Ah that makes more sense.

Well, if y = f(x), the inverse function, f−1(x)f^{-1}(x) is a reflection of the original function across y = x. So you basically take the reciprocal of the gradient of the original function.
Original post by usycool1
Ah that makes more sense.

Well, if y = f(x), the inverse function, f−1(x)f^{-1}(x) is a reflection of the original function across y = x. So you basically take the reciprocal of the gradient of the original function.


So I've spent 3 hours trying to solve it and all it took was that - WHY ?! :frown:

Major thankyou btw ! You're always the hero :smile:


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Original post by usycool1
Ah that makes more sense.

Well, if y = f(x), the inverse function, f−1(x)f^{-1}(x) is a reflection of the original function across y = x. So you basically take the reciprocal of the gradient of the original function.


So are you saying find the gradient of the original dy/dx of f(x) by sticking 7/8 into the function and find the reciprocal of the answer you get ?


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Got the answerrrr :smile: thanks usycool1 :smile:


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Original post by L'Evil Fish
...

Decided to take your advice! :holmes:

Original post by usycool1
...

Hey usy, would you mind editing my university choices? :colondollar: I've put it in the correct format so it's not that much of a hassle for you.

Spoiler

Original post by krishkmistry
Got the answerrrr :smile: thanks usycool1 :smile:


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No worries! :biggrin:

Original post by Felix Felicis

Hey usy, would you mind editing my university choices? :colondollar: I've put it in the correct format so it's not that much of a hassle for you.

Spoiler



Sure thing...mechanical engineering now? :tongue:
made a blog about the last leg of my journey through a levels and my attempt to turn around my grades,followed are appreciated if you have tumblr or id encourage you to at least take a look :smile:
http://thejourneythrougheducation.tumblr.com/
Fighting the urge to make my own 'ask me anything' thread haha.
Original post by mynameisntbobk
Fighting the urge to make my own 'ask me anything' thread haha.


haha I've being doing that for quite some time
Original post by usycool1

Sure thing...mechanical engineering now? :tongue:



:pierre:

For quite some time now, actually. I didn't apply for maths, ultimately, but have only gotten around to changing this now.
Original post by Felix Felicis


:pierre:

For quite some time now, actually. I didn't apply for maths, ultimately, but have only gotten around to changing this now.


I actually had no idea :lol:
Original post by Felix Felicis
Decided to take your advice! :holmes:


Hey usy, would you mind editing my university choices? :colondollar: I've put it in the correct format so it's not that much of a hassle for you.

Spoiler



Well done :smile:
Original post by Robbie242
haha I've being doing that for quite some time


Haha I would have thought you'd have done one already, although I can imagine all the hate you'd get :lol:

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