The Edexcel C1 (16/05/12 - AM) Revision Thread

OP

I believe Transformations of graphs is in C1..

..I can't get my head around it! Can someone explain quick short way to remember what happens

for e.g. y = f(x) + a ..soemthing happens to x or y axis by something blah blah..I can't remember this very good way to remember it.

cheers

F(x) + a = Move up A units

F(x) - a = Move down A units

F(x+a) = Move left A units

F(x-a) = Move right A units

-f(x) = Multiply y coordinates by -1

f(-x) = Multiply x coordinates by -1

af(x) = Multiply y coordinates by a

f(ax) = Multiply x coordinates by 1/a

Reply 181

intellectual1

3

Original post by Wooden

I believe Transformations of graphs is in C1..

..I can't get my head around it! Can someone explain quick short way to remember what happens

for e.g. y = f(x) + a ..soemthing happens to x or y axis by something blah blah..I can't remember this very good way to remember it.

cheers

y = f(x) + a it shifts to the left :smile:

...

just learn the rules carefully! :wink:

Reply 182

yayifications

9

Original post by Wooden

I believe Transformations of graphs is in C1..

..I can't get my head around it! Can someone explain quick short way to remember what happens

for e.g. y = f(x) + a ..soemthing happens to x or y axis by something blah blah..I can't remember this very good way to remember it.

cheers

I remember it like this:
If it's inside the bracket, do the opposite to the x-co-ordinate. E.g. y = f(x-3) would add 3 to the x co-ordinates.
If it's outside the bracket, do what it says to the y-co-ordinate. E.g. y = f(x)+5 would add 5 to the y co-ordinates.

Reply 183

vxrz

7

Original post by pbn

how would you work out the points for it though?
and I've just looked at the answers and they made dy/dx=0 then factorised by putting x as the origin 0, the used quadratic formula to get A and B, then did A-B to get AB; Is this what you meant and I'm just too slow to understand x_x hahah

I thought they had already given you the points. But if they haven't then you differentiate the equation, find out the gradient (by substituting an x-value they must have given you), find out the equation, and then by using the equation work out the coordinates.

So you are right :smile:

Reply 184

intellectual1

3

There's always a question on the

normal, tangent, gradient, use of y-y1 = m (x - x1 )

factorisation of a quadratic very common in the sequences series questions

examiners reports say alot of candidates make careless errors with negative numbers and indices

know your surd and indices rules! :smile:

always a question on this

Reply 185

0range

OP

20

Original post by pbn

how would you work out the points for it though?
and I've just looked at the answers and they made dy/dx=0 then factorised by putting x as the origin 0, the used quadratic formula to get A and B, then did A-B to get AB; Is this what you meant and I'm just too slow to understand x_x hahah

When I did that question I factorised as well
From part A you have to integrate the f'(x) from that you should get

f(x) = 6x -2x^2 - x^3

A and B occur when f(x) is = 0 You have to remember that the points lie on the x axis so there y value must be 0

so you get the eqaution

6x -2x^2 - x^3 = 0

^ Take out the x then use completing the square or qaudratic formula

and you should get the answer

Reply 186

rosie66

how do you work out the area of a triangle on a graph?

Reply 187

0range

OP

20

Btw when your asked to work out the area of a triangle and you don't have the perpindicular hieght what do you do?

Reply 188

vxrz

7

Original post by rosie66

how do you work out the area of a triangle on a graph?

Same way you would work out the are of a normal triangle, but instead of the length being in centimetres, it is going to be in coordinates now.

Reply 189

pbn

Original post by 0range

When I did that question I factorised as well
From part A you have to integrate the f'(x) from that you should get

f(x) = 6x -2x^2 - x^3

A and B occur when f(x) is = 0 You have to remember that the points lie on the x axis so there y value must be 0

so you get the eqaution

6x -2x^2 - x^3 = 0

^ Take out the x then use completing the square or qaudratic formula

and you should get the answer

Thank you! :smile:

have you done a lot of the solomon papers?

Reply 190

usycool1

19

Original post by 0range

Btw when your asked to work out the area of a triangle and you don't have the perpindicular hieght what do you do?

You can work out the perpendicular height :smile:

I will post an example in a second :smile:

Reply 191

rosie66

Original post by usycool1

You can work out the perpendicular height :smile:

I will post an example in a second :smile:

thank you

Reply 192

pbn

Has anyone got a quick list of the most important formulae were supposed to remember?

Reply 193

usycool1

19

Original post by pbn

Has anyone got a quick list of the most important formulae were supposed to remember?

x = \dfrac{-b \pm \sqrt{b^2-4ac}}{2a}

b^2-4ac

And they give us the arithmetic progression formulas :smile:

Reply 194

vxrz

7

Original post by pbn

Has anyone got a quick list of the most important formulae were supposed to remember?

Found this very useful; C1 in a page.

(edited 11 years ago)

C1inEssence.pdf268.9KB

Reply 195

pbn

Original post by usycool1

x = \dfrac{-b \pm \sqrt{b^2-4ac}}{2a}

b^2-4ac

And they give us the arithmetic progression formulas :smile:

Thank you

, after i posted this I realised most of the harder formulae are for C2 anyhow and I already have it thankfully.

Reply 196

pbn

Original post by vxrz

Found this very useful; C1 in a page.

Thank you! Have you got this for any other maths units like C2 or S1? :smile:

Reply 197

rosie66

does any one have an example of how to find the perpendicular height?

Reply 198

amber109

3

Original post by intellectual1

There's always a question on the

normal, tangent, gradient, use of y-y1 = m (x - x1 )

factorisation of a quadratic very common in the sequences series questions

examiners reports say alot of candidates make careless errors with negative numbers and indices

know your surd and indices rules! :smile:

always a question on this

whats the tangent of the normal? does that imply perpendicular?