HARDER 3 UNIT qs (1 Viewer)

sths

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is there anyway to do harder 3 unit questions?

if anybody has any jus put em here plz

thx.......


btw whu rkns inequalities are impossible

and wot do u rkn ur skool will come for the hsc overall in the state?
 

McLake

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Originally posted by sths
and wot do u rkn ur skool will come for the hsc overall in the state?
Edit: 6th (it was 7th last year)
 
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Minai

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he said wat do u think ur skool will come?

im predicting mine in the top 25, based on last yr..
 

spice girl

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No, inequalities are NOT hard. Here are the usual tricks:

1. Bring all to one side and prove either strictly non-negative or non-positive (whether it be <= or >=)

2. Try AM>=GM ALWAYS (even if you can't see it). See a product on one side and a sum on the other? Think AM>=GM. Can't see how it's remotely related to AM>=GM? Simplify and try again.

An example: Given a,b,c > 0 and a+b+c = 1:
Prove (1/a - 1)(1/b - 1)(1/c - 1) >= 8

3. 2 variables x,y, and have a relationship between x, y: Convert inequality to one variable, bring to one side and DIFFERENTIATE!

E.g. x + y = k
Prove 1/(x^2) + 1/(y^2) >= 8 / (k^2)

4. Something with n in the equation (where n is a positive integer), try induction.
 

Lazarus

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I think the majority of 'harder 3u' questions involve probability - I have quite a few at home, will type them up tonight.
 

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