Hardest Topic in 3unit? (1 Viewer)

kurt.physics

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Help with induction please,
I cant get my head around this, could some one please show me why with the following example

1. Prove (Sigma (with n at the top and r= 1 at the bottom) 3-r = (3n - 1) / 2(3n)

I get step 1 but get lost at 3?
 

iEdd

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STEP 1: Sub in n=k

STEP 2: Sk+1= (sub it in to original formula) -(i)

"BUT Sk+1 = Sk + Tk+1" -(ii)

Then you get (i)=(ii) and you have proven it. Is that what you did?
 

theodore223

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id rather die than do cirlce geo. thats the only toic i have given up on and will answer last in the exam. that and shm i dont get.
 

drynxz

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HARDEST TOPIC:?

Bionomial theorem hands down, especially the parts involving the proving of identities and equating coefficients. 4U bionomial theorem (harder 3u) is abosolute hell, mix that with bionomial probability and your gone ><

Some other topics i dont like is, inverse trig and exponencial, growth and decay.
 

Hikari Clover

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回复: Re: Hardest Topic in 3unit?

i changed my mind!!
it should be bionomial stuff!!!
i could not solve any of them in the HSC past papers.....
especially they usually come out in Q7(b),it makes the question even more impossible!!!
 

xclusv2bhung

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Re: 回复: Re: Hardest Topic in 3unit?

dont like inverse functions , probablity`s a bitch bwahah
PLUS , permutations and combinations .. =.="

i think i`ve posted here before ... but ah well , heres to an update.

=]
 

kurt.physics

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Dont like inverse functions from inspection :)

I finally get "Proof by Mathematical Induction" the bit i didnt get was that when we assume for n = k that it comes out as eg 3 + 8 + 15 +....+ k(k+2) = k(k^2 +2)/3 or what ever, then we do n = k+1 i.e. 3 + 8 + 15 +....+ k(k+2) + (k+1)((k+1)+2)
then we could sub k(k^2 +2)/3 instead of the read then solve, i could see how we subed kinda thing, but i get it know;;; im a bit lazy for the next part, instead of making it into the exact first formula i just expand the formula and the k+1 bit + compare


Simple Harmonic motion is easy once you can understand the derivation of it, it took me several pages of doodleing and scribbling till i got to the formula, but i did it :)

Integration is the easiest ever!!! That stuff in my oppinion should be in 2U its so easy and then they could put 4U integration into 3U and put some more Uni core Integration into 4U. I also rekon that they should ditch conics in 4U and put Vectors from calculus or something more interesting


After doing some of the 3U i fell that Advanced Mathematics (2U) isnt advanced at all, infact, it should be called general!

Has every one done their tests yet, when is that, haven't you guys finished high school, what i mean is, will you guys be coming back next term?
 
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slasher3689

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Any 3 unit probability and binomials is the hardest imo... but circle geometry bites ass too...

Induction isnt too bad, at least i can usually get 2/3 for induction questions (I can prove it for n=K+1 sometimes lol, but its just practise...)
 

JasonNg1025

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I reckon parametrics can be hard, but normally in exams they're easier..

I only don't like SHM when there's the tide OR if there's more than one happening xD

Circle Geometry is also quite hard

Induction wastes time in the exam

that's my opinion = )
 

morganforrest

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Any topic beginning with P....Perms&Combs, Parametrics, Probability (because the wording is always so ambiguous), Porjectile Motion (though this really isnt that bad, just some questions that shit me to tears), Polynomials (I'm beginning to like these as I understand them more)

Best Topic ======> Mathematical Induction.....far and away the coolest topic though I must admit Integral Calculus gives it a run for its money sometimes
 

nitnit

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can i say the whole one unit course is difficult!?!?

ahh its killing and wasting my time!!

so glad it will be over in a few days time!!

good luck everyone!

but i absolutely HATE HATE AHTE binomal and then projectile.. yuck!
 

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