C1 MEI Wednesday 16th May 2012

Original post by Benniboi1

Very true

if you do further maths then then you have FP2 to look forward to next year :colone:

Gah, I only do Maths because i am a pathetic excuse of a human being. :'(

Reply 22

Original post by AspiringGenius

Well thanks anyway, you're probably right. I'm going to ask my tutor if this is the correct use of the factor theorum. I'm also going to ask about remainder theorum. If there's anything different then i'll post :smile:

Ohh please do post if you find anything it would be most helpful!
I'm not going into school until the exam so I won't have chance to ask!
Going to do another past paper or two tomorrow to make sure I fully understand everything!

Reply 23

AspiringGenius

Original post by Alotties

Ohh please do post if you find anything it would be most helpful!
I'm not going into school until the exam so I won't have chance to ask!
Going to do another past paper or two tomorrow to make sure I fully understand everything!

ok I have consulted the great holy scriptures of the MEI textbook. :worship:

Most polynomial equations do not have integer (or fraction) solutions. It is only a few special cases that work out nicely.

To check whether an integer root exists for any equation, look at the constant term. Decide what whole numbers divide into it, and test them.

Now that isn't the factor theorum, but it does give us an idea on how to approach the polynomial without making random guesses (or attempting to justify an observation).

the book doesn't give anything about finding a root using the factor theorum when we don't really know what a possible factor of a cubic or greater order polynomial is.

I quote:

It is often possible to find one factor or mroe by "spotting" it, or by sketching the curve

Which shows both fo our methods is correct. however using the method of anylysing the constant, and it's factors, you have more leverage in starting an investigation.

The mark scheme gave marks for:

trials of at calculating f(x) for at
least one factor of 30

details of calculation for f(2) or
f(−3) or f(−5)

attempt at division by (x − 2) as
far as x3 − 2x2 in working

correctly obtaining x2 + 8x + 15

factorising a correct quadratic
factor

(x − 2)(x + 3)(x + 5)

Which shows although we would both have gotten marks, we both went about it in a slightly cantankerous way. By using the method of experimenting using factors of the constant, we make our lives much easier, and make our working mroe fluid. :smile:

Reply 24

Original post by AspiringGenius

ok I have consulted the great holy scriptures of the MEI textbook. :worship:

Most polynomial equations do not have integer (or fraction) solutions. It is only a few special cases that work out nicely.

To check whether an integer root exists for any equation, look at the constant term. Decide what whole numbers divide into it, and test them.

Now that isn't the factor theorum, but it does give us an idea on how to approach the polynomial without making random guesses (or attempting to justify an observation).

the book doesn't give anything about finding a root using the factor theorum when we don't really know what a possible factor of a cubic or greater order polynomial is.

I quote:

It is often possible to find one factor or mroe by "spotting" it, or by sketching the curve

Which shows both fo our methods is correct. however using the method of anylysing the constant, and it's factors, you have more leverage in starting an investigation.

The mark scheme gave marks for:

trials of at calculating f(x) for at
least one factor of 30

details of calculation for f(2) or
f(−3) or f(−5)

attempt at division by (x − 2) as
far as x3 − 2x2 in working

correctly obtaining x2 + 8x + 15

factorising a correct quadratic
factor

(x − 2)(x + 3)(x + 5)

Which shows although we would both have gotten marks, we both went about it in a slightly cantankerous way. By using the method of experimenting using factors of the constant, we make our lives much easier, and make our working mroe fluid. :smile:

Ohh I see

That makes a lot of sense, better than randomly guessing or trying to work it out because you have a few points to start from! :tongue:

Reply 25

AspiringGenius

Original post by Alotties

Ohh I see

That makes a lot of sense, better than randomly guessing or trying to work it out because you have a few points to start from! :tongue:

so in the case of, x^3 + 6x^2 - x - 30,
we know that a root must be:
x=plusminus1
x=plusminus2
x=plusminus3
x=plusminus5
x=plusminus6
x=plusminus10
x=plusminus15
x=plusminus30

then we can apply the factor theorum which is:

If (x-a) is a factor of f(x), then f(a)=0 and x=a is a root of the equation f(x)=0

so if x=2 is a factor of f(x), then f(a) must equal 0. It does and hence x=2 is a factor.

To fully factorise you then do polynomial long division with (x-2) and ta da! :biggrin:

I hate proof!

Original post by Axion

I hate proof!

I REALLY CAN'T DO PROOF QUESTIONS, it's like wth are you asking me to do :|
any tips guys? Fml

Reply 28

SugarLips.

Original post by jordan95

Just created this thread for people who will be sitting the MEI C1 (4751) exam on Wednesday 16th May.

I'm resitting after getting 78 UMS in the January exam; I'm quite optimistic this time round, but with the unpredictable nature of MEI who knows what monstrosities could find their way into the exam paper. :unimpressed:

That being said, I have found that, on most papers, for a lot of the 'more difficult' questions (those towards the end of Section B) the key tends to lie with a quadratic equation.

Anyway, aiming for 100 UMS on this paper! I hope it goes well for everyone else too! :smile:

DAMN YOU! You beat me to it, I was just about to create a thread for this exam!

Reply 29

When doing binomial expansion if the question doesn't specify what order the powers go in, it doesn't matter whether you arrange them ascending or descending right?
I've done mine ascending in one paper and the mark scheme lists them descending but the question doesn't specify that it wants them descending so I'd still get full marks right? :confused:

Reply 30

Original post by SugarLips.

I REALLY CAN'T DO PROOF QUESTIONS, it's like wth are you asking me to do :|
any tips guys? Fml

I also hate proofs! I hope one doesn't come up, or if one does, it is only worth like 2 marks xD
I hate them so much!

Reply 31

Axion

The c1 Jan 2012 A grade boudnary was 59/72

Reply 32

I don't think I'm prepared enough for getting an A.
The maths department at my school isn't very strong.
There are 8 of us resitting this unit, out of 14 of us in the class.
The other 7 people sitting it with me all got U's (the other results in my class were 1 A (on the mark), 2 B's and 3 C's) so I didn't attend the catch up lessons for the exam because they're all so far behind and just trying to get an E :tongue:

I'm more nervous for this than I was for my bio resit yesterday, just because I've put less work in.

(yes I am talking to myself, I think my twitter followers are getting annoyed at my constant exam tweets :colondollar:

)

Reply 33

Original post by Axion

The c1 Jan 2012 A grade boudnary was 59/72

I got 55 in Jan :colondollar:

Did you take it then? :smile:

Reply 34

Axion

Original post by Alotties

I got 55 in Jan :colondollar:

Did you take it then? :smile:

Nah Im taking it for the first time tomorrow, but found that on internet.

Some papers are so muche asier than others.

Also, i will be flopping C2 on friday :smile:

Reply 35