Mega A Level Maths Thread MK II

Original post by DJMayes

Don't do

\dfrac{dy}{d\theta }

- do

\dfrac{d(y^2)}{d\theta }

. If Y is not changing then y^2 is also not changing, making the two interchangeable. However, in this circumstance y^2 is a lot easier to work with.

I also tried that, but I can't find what I've done wrong, and I don't get what the mark scheme does

Reply 7982

Last ever A-level maths exam on Friday - M4. Mixed emotions..

Reply 7983

Original post by MathsNerd1

Why don't I ever think of these :redface:

Did you ever have M1 vectors questions about finding the shortest distance between two moving things? If so, did you ever find the maximum value of the distance squared rather than the maximum value of the distance, in order to take life easier due to less surds? This is a very similar idea but applied to polar co-ordinates instead of vectors.

Reply 7984

Arva

14

Original post by yl95

Thanks, everyone!
Also, just curious -- how much of a 'big step' did M3, S2 and the FP modules seem to you guys? I'm starting them after my exams.

Fp2 and 3 aren't too bad, but M3 is demonic - a huge step up from M2.

Reply 7985

Original post by CD315

Last ever A-level maths exam on Friday - M4. Mixed emotions..

I have that tomorrow (On Edexcel), will still have four more Maths exams to go though. :lol:

Reply 7986

Kvothe the Arcane

20

I have some homework for tomorrow (a couple exercises) on polar coordinates. I'm not sure what they are but I spied that it's an Fp2 topic so I'll look tonight after C4 revision! :smile:

Reply 7987

Original post by DJMayes

I have that tomorrow (On Edexcel), will still have four more Maths exams to go though. :lol:

As far as I'm aware, your M4 is significantly more interesting/harder than mine. Mine's easier than our M3 :lol:

Reply 7988

Original post by CD315

As far as I'm aware, your M4 is significantly more interesting/harder than mine. Mine's easier than our M3 :lol:

The topics we have are:

- Relative motion
- Two dimensional collisions between spheres
- First Order Differential Equations in Mechanics
- Second Order Differential Equations in Mechanics
- Stability

Reply 7989

JenniS

Original post by JenniS

I also tried that, but I can't find what I've done wrong, and I don't get what the mark scheme does

Original post by DJMayes

I have that tomorrow (On Edexcel), will still have four more Maths exams to go though. :lol:

ah man I'd been half integrating and differentiating at the same time, it wasn't even that hard ahhhh thanks

Reply 7990

Revengeissweet

he curve C shown in Fig. 1 has polar equation
r = a(3 + Ö5 cos q ), -p £ q < p.

(a) Find the polar coordinates of the points P and Q where the tangents to C are parallel to the initial line.
(6)
The curve C represents the perimeter of the surface of a swimming pool. The direct distance from P to Q is 20 m.

(b) Calculate the value of a.

Okay I attempted copying and pasting and it came out slightly funny it's meant to be root5costheta
For part b) Why cannot I use 8a=20 as I thought the radius was the distance. I'm getting confused...

Reply 7991

MathsNerd1

17

Original post by DJMayes

Did you ever have M1 vectors questions about finding the shortest distance between two moving things? If so, did you ever find the maximum value of the distance squared rather than the maximum value of the distance, in order to take life easier due to less surds? This is a very similar idea but applied to polar co-ordinates instead of vectors.

Oh I never thought of it like that really, but I never make life easier for myself, just use a sledgehammer to break open a walnut really :tongue:

As long as it gets me the correct answer then its fine by me as I usually have time spare in the exams even FP2 :biggrin:

Reply 7992

username638250

7

Original post by Arva

Fp2 and 3 aren't too bad, but M3 is demonic - a huge step up from M2.

Oh no! I suck at Mechanics so this should be...fun...

Reply 7993

tigerz

I've joined this weird thing at school (chose maths ofc), I open up the booklet, see this and thought: what have I gotten myself into? :/

Let ABC be a triangle with <BCA = 90°, and let D be the foot of the altitude from C. Let X be a point in the interior of the segment CD. Let K be the point on the segment AX such that BK = BC.
Similarly, let L be the point on the segment BX such that AL = AC. Let M be the point of intersection of AL and BK. Show that MK = ML.

Thank god I don't have to solve it :redface:

Reply 7994

Original post by DJMayes

The topics we have are:

- Relative motion
- Two dimensional collisions between spheres
- First Order Differential Equations in Mechanics
- Second Order Differential Equations in Mechanics
- Stability

We have relative motion in M3, and the only time differential equations ever come up in mechanics is on M2 (simple differential equations at that).

Our topics are;

- Centre of mass (proving by calculus from first principles is in there, probably the best part)
- Force Systems
- Frameworks
- Dimensions
- Gravitation
- Circular motion (banked and vertical)
- 2D collisions

Reply 7995

Original post by CD315

We have relative motion in M3, and the only time differential equations ever come up in mechanics is on M2 (simple differential equations at that).

Our topics are;

- Centre of mass (proving by calculus from first principles is in there, probably the best part)
- Force Systems
- Frameworks
- Dimensions
- Gravitation
- Circular motion (banked and vertical)
- 2D collisions

Centres of mass are in our M2 and M3. Force systems and frameworks are M5 if we're thinking same thing (Vector moments, couples). Dimensional analysis (If that's what you're referring to) isn't in there. Gravitation is M3, as is circular motion. We share 2D collisions though!

Reply 7996