• Coming soon...BoS Trial exams
    Watch this space!

Class of 2025 (2025 HSC CHAT) (5 Viewers)

alphxreturns

Well-Known Member
Joined
Oct 22, 2024
Messages
515
Gender
Male
HSC
2025
nah like prove 2n c n = so and so
the 'given (1+x)^2n = (1+x)^n (1+x)^n'?

look for coefficients, look for substitutions for x, look for anything thats recognisable from either lhs or rhs. like derivatives or integrals
 

alphxreturns

Well-Known Member
Joined
Oct 22, 2024
Messages
515
Gender
Male
HSC
2025
(1+X)^(2n+1) = (1+X)(1+X)^2n

expanding LHS

(2n+1)C0 Γ— X^0 + (2n+1)C1 Γ— X^1 + ... + (2n+1)Cn Γ— X^n + ... + (2n+1)C(2n+1) Γ— X^2n+1

symmetry of Pascal's triangle means nC0 = nCn
and so on, (2n+1)C0 = (2n+1)C(2n+1)

so since 2n+1 is odd, (sub n = any number if u want proof)
letting X = 1,
the expansion is 2((2n+1)C0 + ... + (2n+1)Cn)
rhs = (1+1)(1+1)^2n

so 2n+1C0 +...+ 2n+1Cn = 4^n

sorry I'm pressed on time but the main part was symmetry and X=1
 

ros545

New Member
Joined
Nov 11, 2024
Messages
13
Gender
Undisclosed
HSC
2022
Hey, is early entry for UTS closing today at 11:59pm (7th September) or tomorrow at 11:59pm (8th September)?
Thanks
 

bigupsanky

Active Member
Joined
Jul 1, 2025
Messages
283
Gender
Male
HSC
2025
(1+X)^(2n+1) = (1+X)(1+X)^2n

expanding LHS

(2n+1)C0 Γ— X^0 + (2n+1)C1 Γ— X^1 + ... + (2n+1)Cn Γ— X^n + ... + (2n+1)C(2n+1) Γ— X^2n+1

symmetry of Pascal's triangle means nC0 = nCn
and so on, (2n+1)C0 = (2n+1)C(2n+1)

so since 2n+1 is odd, (sub n = any number if u want proof)
letting X = 1,
the expansion is 2((2n+1)C0 + ... + (2n+1)Cn)
rhs = (1+1)(1+1)^2n

so 2n+1C0 +...+ 2n+1Cn = 4^n

sorry I'm pressed on time but the main part was symmetry and X=1
oh ye u right ty ty
 

mookie9882882

Member
Joined
Jul 25, 2025
Messages
24
Gender
Female
HSC
2025
guys i need good pen recs my handwriting is shit and i need a pen thats not too inky but also really good
 

ros545

New Member
Joined
Nov 11, 2024
Messages
13
Gender
Undisclosed
HSC
2022
Is early entry for UTS closing today at 11:59pm (7th September) or tomorrow at 11:59pm (8th September)?
Thanks
 

Dresden

New Member
Joined
Oct 9, 2024
Messages
5
Gender
Male
HSC
2025
yup

they havent updated for 2025 or anything after 2021 for legal tbh
I think they've just stopped updating the site tbh because I uploaded all my Prelim and now Trial papers for Legal and none got put on the site, same for EES.
 

bigupsanky

Active Member
Joined
Jul 1, 2025
Messages
283
Gender
Male
HSC
2025
guys i need good pen recs my handwriting is shit and i need a pen thats not too inky but also really good
stageek 6 pack 13.90 on amazon or proed pens (ask a friend who goes to proficiency education tutoring for free pens). Also try bic gelocity very good
 

reniiiblaseee

Well-Known Member
Joined
Mar 27, 2025
Messages
334
Gender
Female
HSC
2025
From now I’m back into study soo
Attempting at least 8hrs each for Saturday + Sunday
Then abt 4 for school days but school draining asf πŸ’”
Wbu
well i have one more trial exam to go b4 i start the hsc grind so im hoping for 6-8h a day, maybe 4-5 on school days considering events like graduation will come in
 

Kat.crazi

π“‡π‘’π“π‘’π’Άπ“ˆπ‘’ 𝓂𝑒
Joined
Aug 25, 2024
Messages
748
Gender
Female
HSC
2025
well i have one more trial exam to go b4 i start the hsc grind so im hoping for 6-8h a day, maybe 4-5 on school days considering events like graduation will come in
Very solid good luck !
 

Users Who Are Viewing This Thread (Users: 0, Guests: 5)

Top