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Reply 80
Original post by ak395
Ok... thnx for that... i do like differentiation but i just looked at the book and all the weird symbols are scaring me but i guess ill take it as it goes... i have 93 average ums for my as level and i think *hope* i did well in m1 so i can afford to get slightly lower... ok i know u r probs not very interested but this is my form of calming myself down :colondollar:


Just try to achieve your best!!
Original post by Eternal*
Need an A x

Yu?


likewise :frown: its really beginning to stress me out especially after january's performance lol x
Reply 82
my teacher thinks that this would be a hard paper ? and he said there could be a big question like differentiation/trig
when they c3 will be difficult like how cause all the papers seem to look same? which paper was the hardest till now?
Reply 83
Original post by otrivine
my teacher thinks that this would be a hard paper ? and he said there could be a big question like differentiation/trig
when they c3 will be difficult like how cause all the papers seem to look same? which paper was the hardest till now?


Trigonometry and Differentiation are both very 'big' chapters so we must expect 'big' questions involving these two chapters.
Reply 84
Original post by M Kh
Trigonometry and Differentiation are both very 'big' chapters so we must expect 'big' questions involving these two chapters.


but like which paper was the most difficult till now?
Reply 85
Original post by Souriretoujours


likewise :frown: its really beginning to stress me out especially after january's performance lol x


:ditto:

S2 didnt go too well either...
I need an average of 83UMS on S2 C3 C4
Original post by Eternal*
:ditto:

S2 didnt go too well either...
I need an average of 83UMS on S2 C3 C4


Yeah I repeated M1 in early may hoping to have got at least 70 UMS. S1 went really well so hoping for85-90 UMS which would leave me needing about 75 in C3 and C4 :frown: but I'm terrible at both of them so :frown:
Reply 87
I'm regretting resitting this paper, it's actually rather difficult in places... Hopefully a past paper a day will be enough.
Reply 88
Original post by Souriretoujours
Yeah I repeated M1 in early may hoping to have got at least 70 UMS. S1 went really well so hoping for85-90 UMS which would leave me needing about 75 in C3 and C4 :frown: but I'm terrible at both of them so :frown:


:goodluck:
Reply 89
I need around 68 in C3 and C4 to get an A but C3 atm is really starting to annoy me :frown:
Reply 90
Original post by otrivine
but like which paper was the most difficult till now?


I am not sure really - it just depends on you. Maybe check the grade boundaries to see which was the hardest paper?
Reply 91
Original post by M Kh
I am not sure really - it just depends on you. Maybe check the grade boundaries to see which was the hardest paper?


jan 11 was quite hard imo...and jan 10.
(edited 11 years ago)
Reply 92
Original post by grazie
For part a), given that

y=arccosxy=\arccos x

Then

x=cosyx=\cos y

And the cosine of an angle is the same as the sin(π2\frac{\pi}{2} - angle). So...

x=sin(π2y)x=\sin(\frac{\pi}{2}-y)

Taking arcsin on both sides

arcsinx=(π2y)\arcsin x=(\frac{\pi}{2}-y)

For part b), you're given arccos x in part a) and then worked out arcsin x. So

arccosx+arcsinx=y+(π2y)\arccos x + \arcsin x=y + (\frac{\pi}{2}-y)
=π2=\frac{\pi}{2}

I think the problem with this question is that few (or perhaps none) examples are given in the textbook.


ah ok thank you:biggrin:

Yeah the problem was that i had never come across a problem like that before
Reply 93
Original post by -James-
jan 11 was quite hard imo...and jan 10.


Yea, good luck revising.
Reply 94
Original post by emmaaa88
I'm confused by this question in my textbook, I know it's just modulus but any help would be appreciated! :smile:

Sketch this graph:
y = |x+4| + |x-1|

Also does anyone have any useful ways of remembering the vector transformations because I am not good at those!


I have no idea how to sketch y = |x+4| + |x-1| tbh, that's mad hard.

But if you're asking about graph transformations (I assumed that's what you meant by vector transformations?), then I remember how to do graph transformations using this:

If y=f(x) and 'a' is a number, then perform the following actions to the graph:

y = af(x) -----> Multiply all y-coordinates by 'a'
y = f(x) + a -----> Add 'a' to all y-coordinates
y = f(ax) -----> Multiply all x-coordinates by '1/a'
y = f(x+a) -----> SUBTRACT 'a' from all x-coordinates.



Also, for me, I do graph transformations step-by-step and do the things closest to the 'x' first / using BIDMAS, so, if it gives you y = f(x) and says draw the graph of:

y = 2f(3x) - 5

I draw the graph of y=f(3x) first, by multiplying all x-coordinates by '1/3',

then I draw the graph of y = 2f(3x) by multiplying all y-coordinates by '2',

then I draw the final graph of y = 2f(3x) - 5 by subtracting '5' from all y-coordinates, which is the graph they're looking for.

Hope that helps a bit
(edited 11 years ago)
Reply 95
anyone wanna explain the reasoning why this (the last part at the bottom) is wrong?



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Sorry about the crappy quality of the image lol
Original post by arnab
anyone wanna explain the reasoning why this (the last part at the bottom) is wrong?



Uploaded with ImageShack.us

Sorry about the crappy quality of the image lol


When you apply a function to an equation, it must be applied to the whole of each individual side, as you would when dividing each side of an equation or multiplying each side of an equation. Hence you can't apply logarithms like that.

i.e. The second line should read ln(e^x + 3e^(-x)) = ln(4) which you can't do anything with.

You can solve this like so:

e^x + 3e^(-x) = 4

Multiply through by e^x

e^2x + 3 = 4e^x
e^2x - 4e^x + 3 = 0

Solve as you would a quadratic

(e^x - 1)(e^x - 3) = 0

e^x = 1, 3
x = ln(1), ln(3)
x = 0, 1.0986...
(edited 11 years ago)
Reply 97
Original post by M Kh
Yea, good luck revising.


I thought compared to Jun 11 and Jan 12.

did you find them easy?
any1 on here done the solomon papers for c3?
Right, it's now time to get 90ums+ for my A*. Hopefully I can pull it off..

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