Edexcel C2 20th May 2015 Official Thread

Reply 620

Ahsen2015

1

Original post by physicsmaths

Im an intruder just here to help as I sat it last year.

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what did you get? any tips?

Reply 621

thenextchemist

21

Original post by IvoryToast

They are using the formula, it's just 2000 is year 1 so 2002 is the 3rd year

The forumla to find a term is
ar^n-1

Right?

They use ar^n

I understand that some questions do this, but how would you know the difference

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Reply 622

username1162972

18

Original post by Ahsen2015

what did you get? any tips?

Got 94 or 96 not sure but i dropped marks for using tanx=cosx/sinx in a trig question.

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Reply 623

ezrad

what does tanx= anyone pls

(edited 8 years ago)

Reply 624

husband material

2

Original post by ezrad

what does tanx= anyone pls

Sinx/cosx

Or

1/cotx

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Reply 625

tw15st3d

17

hey if i have the inequality: -1.035^n>= -2.353

I can make both sides positive by multiplying by -1 right?

and then this means i switch the sign around right? because when doing an exam solutions video, the sign doesnt seem to change?

Reply 626

pearl_rose

16

Original post by husband material

Sinx/cosx

Or

1/cotx

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Cot isn't introduced till c3 right? So just sin x/cos x is enough isn't it

Reply 627

Columbo97

OP

2

Original post by tw15st3d

hey if i have the inequality: -1.035^n>= -2.353

I can make both sides positive by multiplying by -1 right?

and then this means i switch the sign around right? because when doing an exam solutions video, the sign doesnt seem to change?

I think you can but that power n worries me.. so don't take my word for it.

What i would say is just lob it into logs and change it at the end :smile:

log_-1.035 -2.353 = n

EDIT: The above log is impossible due to the minus base. I think you have to multiply by -1.

(edited 8 years ago)

Reply 628

frozo123

12

Original post by husband material

Sinx/cosx

Or

1/cotx

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Or the square root of sec^2x -1

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Reply 629

Columbo97

OP

2

Original post by frozo123

Or the square root of sec^2x -1

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We haven't learnt Cot or Sec yet, only sin cos and tan.

Reply 630

frozo123

12

Original post by Columbo97

We haven't learnt Cot or Sec yet, only sin cos and tan.

What equations in c2 do we need to learn? The SA and Volume ones? may you let me know? Thankyou

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Reply 631

pearl_rose

16

Original post by gdunne42

Absolutely no reason to lose all marks. They usually start with a show that for 4 or so marks. If you can't do that successfully, you can still get the 8+ marks for differentiating the formula given, solving to find the value of the variable that makes the differentiated equation = 0, differentiating again to prove its a max or min and then substituting it in to find the max/min value of the perimeter/area/volume you have been working on.

You need:
perimeters and areas of rectangles, right and non-right angle triangles, trapezia, circles, semicircles, sectors and composite shapes and
volume of cuboid, cyclinder and prisms.

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:]] Thanks so much!!! So I have to memorize the formula for all of those?

Reply 632

Columbo97

OP

2

Original post by frozo123

What equations in c2 do we need to learn? The SA and Volume ones? may you let me know? Thankyou

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Equation OF A CIRCLE
(x-a)^2 + (y-b)^2 = r^2

SINE RULE
SinA/a = SinB/b = SinC/c OR a/SinA = b/SinB...etc

COSINE RULE
a^2 = b^2 + c^2 - 2bcCosA OR CosA = b^2 + c^2 - a^2/2bc

AREA OF A TRIANGLE
1/2abSinC OR 1/2bcSinA OR 1/2acSinB

LOGARITHMS
log n (base a) = x => a^x = n - re arranging the logarithm
log x + log y = log (xy) - multiplication law
log x - log y = log (x/y) - division law
log (x)^k = k log x - powers law

RADIAN MEASURE
Length of an arc = rx (x being the angle in radians)
Area of a Sector = 1/2 r^2 x
Area of a Segment = 1/2 r^2 (x - Sinx)

TRIGONOMETRIC RULES
tan x = sin x/cos x
cos^2 x = 1 - sin^2 x
sin^2 x = 1 - cos^2 x

Reply 633

Ahsen2015

1

Has anyone tried the solomon papers??

Reply 634

ToLiveInADream

17

Hey guys, I'm praying applications of differentiation doesn't come up! I don't mind the differentiating bit, but the learning SA/Volume formulas suck.

What list of volume + SA formulas should we know? I'm thinking - cylinders, cones, etc..(some are pretty easy to simply work out eg. sphere & rectangle).

Reply 635

ToLiveInADream

17

Original post by Ahsen2015

Has anyone tried the solomon papers??

Yeah, not too bad. I'd recommend going on mathsandphysics's website and trying their gold papers! They're basically real exam questions but they have purposefully picked out harder ones from over the years. If you can do them easily, you're prepared for the exam :smile:

Reply 636

SOREN_TORETTO

3

I know its too late i got only 2 days how am I going to prepare :frown:

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Reply 637

Columbo97

OP

2

Original post by ToLiveInADream

Hey guys, I'm praying applications of differentiation doesn't come up! I don't mind the differentiating bit, but the learning SA/Volume formulas suck.

What list of volume + SA formulas should we know? I'm thinking - cylinders, cones, etc..(some are pretty easy to simply work out eg. sphere & rectangle).