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FP2 MEI OCR Official Thread - 23rd June 2014

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Original post by mathematigeek
Okay, so you know the unit vector is v, this has magnitude 1. You also know the eigen value is 5. This is now M since it satisfies the characteristics equation of M. So the magnitude of M2v is simply 1*52 so 25. The same method is applied to M-1v giving magnitude 0.2. Both are in the direction of v since the eigen value is a scalar quantity.

Hope this helps


How do we know the unit vector is v? and is it always eigenvalue to the power of n?
Original post by mathematigeek
I actually find finding eigen vectors the hardest part of fp2, does anyone know a way to check if you got them right in the exam?

And as for tricky questions, with matrices, the only other tricky part is finding general solutions? Idk :/ and then other tricky parts are C+jS (recognising the type of series) and I find complex roots quite tricky. Calculus and polar curves is all about technique. Hyperbolics are nice too so yea :/


When you say general solutions, do you mean putting x,y and z in terms of parameters when three simultaneous equations have an infinite number of solutions?
Original post by pujah0ntas
How do we know the unit vector is v? and is it always eigenvalue to the power of n?

Because you are asked to find a vector, v, of unit length, hence unit vector. And yes :smile:
Original post by Rex Regum
When you say general solutions, do you mean putting x,y and z in terms of parameters when three simultaneous equations have an infinite number of solutions?

Yes, precisely
Original post by mathematigeek
Because you are asked to find a vector, v, of unit length, hence unit vector. And yes :smile:


hmmmm I'll just go with it for now lul, thanks tho!
Anyone's university offers riding on this exam? :tongue:
Original post by theCreator
Anyone's university offers riding on this exam? :tongue:

Mine :frown: I basically need 100 :'(
Original post by mathematigeek
Mine :frown: I basically need 100 :'(

What uni/course? :smile:

For an A* in Further Maths I think I'll need around 100 UMS in FP2 after DE and S2 :lol:
in the past paper from june 2011 question 4i, i don't understand how the plus/minus has been taken out of the ln(x+-r(x^2-1)). what proves the negative is invalid?
Original post by ineedhelp12345
in the past paper from june 2011 question 4i, i don't understand how the plus/minus has been taken out of the ln(x+-r(x^2-1)). what proves the negative is invalid?


since y>=0 then e^y>=1 and hence if it was x - r(x^2 - 1) then that would be smaller than 1.
Original post by Law-Hopeful
What uni/course? :smile:

For an A* in Further Maths I think I'll need around 100 UMS in FP2 after DE and S2 :lol:

Warwick maths :/ you? And yea, after M2/D2, FP 2 is my only hope :/
June 11, 2 a) I don't understand how on the mark scheme they get from their sin5x/cos5x to the given results? Where do the t's come from?
Original post by mathematigeek
Warwick maths :/ you? And yea, after M2/D2, FP 2 is my only hope :/

Oh nice, Law at Cambridge for me :smile:

I'm sure you'll be fine, you certainly seem to know your stuff anyway! :tongue:
Original post by mathematigeek
June 11, 2 a) I don't understand how on the mark scheme they get from their sin5x/cos5x to the given results? Where do the t's come from?


Omg I spent about an hour last night trying to do that, have no idea how they did it. Really hard question :frown:
Original post by Law-Hopeful
Oh nice, Law at Cambridge for me :smile:

I'm sure you'll be fine, you certainly seem to know your stuff anyway! :tongue:

Thats impressive! Congratulations on getting an offer, thats really amazing! And hmm, ive worked hard but i get caught out on the simplest of things. Please can you help me with the question above?
Original post by theCreator
Omg I spent about an hour last night trying to do that, have no idea how they did it. Really hard question :frown:

I am so confused :frown: I get to that part then they just jump to the conclusion and im so confused :frown:
Original post by theCreator
Omg I spent about an hour last night trying to do that, have no idea how they did it. Really hard question :frown:


Original post by mathematigeek
June 11, 2 a) I don't understand how on the mark scheme they get from their sin5x/cos5x to the given results? Where do the t's come from?

divide top and bottom by cos^5(theta)
Original post by Kim-Jong-Illest
divide top and bottom by cos^5(theta)

Thank you so much! Do you always divide top and bottom by highest power of cos? Or is it sometimes sin? Sorry, its something im worrying about now :frown:
Original post by mathematigeek
Thank you so much! Do you always divide top and bottom by highest power of cos? Or is it sometimes sin? Sorry, its something im worrying about now :frown:

yeah you normally just do that and it works out nicely. it will hardly ever be sin because then you get cot(theta) which is harder to sort out afterwards.
Original post by mathematigeek
Mine :frown: I basically need 100 :'(


Does your offer include an A* in further maths? :eek:

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