C3 Jan 11 Edexcel - Solutions and Paper in the first post (Now On) + TIPS

Ah right ok. I really S1, if you know it, its easy marks. These days Im debating whether to take M1 or S3 for FM. Self taught for FM you mean?

S1 is boring though. It's easy as hell though.

How about this question on the A to L papers, I heard that this probably won't come up but try this.
Use proof by contradiction to prove that log2 3 is irrational
and this one which might be there
Giving your answers to 2 decimal places, solve the simultaneous equations
e^2y ? x + 2 = 0
ln (x + 3) ? 2y ? 1 = 0

I have that exam too, I've noticed that some questions each year are very similar ..so if anyone finds a hard, unusual question, feel free to post it on here There was one unusual question on one of the 2010 papers which included e^x and a 3^x and was worth 5 marks

I remember last year when I was in year 12 everyone in the year above was panicking so much about that question. They forogt that 3^x=e^ln3*x.

Ok how about these questions I just made it up. This'll probably be around 12 marks though this would be the harder questions in the paper.

a. Find dy/dx of f(x)=[1/2arcsin(x)]+2e^2 in terms of x and find the value of dy/dx at 0.4
b. Sketch a graph of f(x)
c. Why are there no stationary points in the graph f(x)
d. What type of function is this

a) for this you could either use the derivative of arcsin(x) directly. Or, seeing that this is a C3 exam thread, rewrite f(x) as sin(2y-4e^2)=x and find dx/dy and invert to find dy/dx. Then use
$[br]\sin^{2}\theta + \cos^{2}\theta = 1[br]$
To find dy/dx in terms of x only.
b) Sketching f(x) it just stretch scale factor 0/5 parallel to y axis i.e. 1/2 y coordinates and translate upwards by 2e^2.
c)no stationary points as dy/dx has no solutions for (dy/dx)=0
d)Not sure what you are trying to get at with this question. Whether it is odd or even?

I mean mapping oops.

Well obviously because arcsin is the inverse function of sin then it is a one to one mapping

One to many. Think about it one x value has many y values.

arcsin IS A ONE TO ONE MAPPING. It is an inverse of the sin function.

Inverse trigonometric functions are multiple-valued because trigonometric functions are periodic as sinx=sin(180-x) therefore one y value is more than one x value. in the inverse function it will be the opposite i.e. one x value is more than one y value. That is why it is one to many.
y=x^2 is many to one so y=x^1/2 will be one to many.
It will only be one to one if the range of arcsinx is from -pi/2<y<pi/2.
Sine isn't one to one

But the principal values are always taken from -pi/2 to pi/2.

Does anyone have any hard questions that may come up in this test?

Well I was helping someone the other day on the OCR syllabus (not MEI) for the
C3 Jan 2010 paper. Although it had some C4 edexcel in it, it had some great C3 questions. They weren't particularly hard but they were worded differently to what we would get for Edexcel.