• Best of luck to the class of 2024 for their HSC exams. You got this!
    Let us know your thoughts on the HSC exams here
  • YOU can help the next generation of students in the community!
    Share your trial papers and notes on our Notes & Resources page
MedVision ad

Prelim 2016 Maths Help Thread (3 Viewers)

Status
Not open for further replies.

Green Yoda

Hi Φ
Joined
Mar 28, 2015
Messages
2,859
Gender
Male
HSC
2017
help:
prove that
(sin^2(a)*cos^2(b))-(cos^2(a)*sin^2(b))=sin^2(a)-sin^2(b)
 

InteGrand

Well-Known Member
Joined
Dec 11, 2014
Messages
6,109
Gender
Male
HSC
N/A
bruh this is purely 2u yr 11 trig.......I dunno differentiation yet lol
Can you do it another way?
Yes. (Sorry, forgot this was in prelim thread and you hadn't learnt calculus yet.)
 

clareh08

New Member
Joined
Aug 27, 2014
Messages
11
Gender
Female
HSC
2015
If in 2014, the Australias population was 23 246 692, with a growth rate of approximately 1.14%, what was the population in 2015?

Please help! What is the formula and how would you work out this question
 

KingOfActing

lukewarm mess
Joined
Oct 31, 2015
Messages
1,016
Location
Sydney
Gender
Male
HSC
2016
If in 2014, the Australias population was 23 246 692, with a growth rate of approximately 1.14%, what was the population in 2015?

Please help! What is the formula and how would you work out this question
Unless there's something I'm missing, isn't it just 23,246,692*(1+0.0114) = 23511704.3, and since you can't have 0.3 of a person, the answer is 23,511,704



Here the initial measurement was 23 246 692, and 1 year passed.
 

Green Yoda

Hi Φ
Joined
Mar 28, 2015
Messages
2,859
Gender
Male
HSC
2017
Help:
prove sin^2(θ)tan(θ)+cos^2(θ)cot(θ)+2sin(θ)cos(θ) = tan(θ)+cot(θ)

My working out so far:
LHS=(1-cos^2(θ))tan(θ)+cos^2(θ)cot(θ)+2sin(θ)cos(θ)
=tan(θ)-sin(θ)cos(θ)+cos^2(θ)cot(θ)+2sin(θ)cos(θ)
=tan(θ)+cos^2(θ)cot(θ)+sin(θ)cos(θ)
 

parad0xica

Active Member
Joined
Mar 24, 2016
Messages
204
Gender
Male
HSC
N/A
Help:
prove sin^2(θ)tan(θ)+cos^2(θ)cot(θ)+2sin(θ)cos(θ) = tan(θ)+cot(θ)

My working out so far:
LHS=(1-cos^2(θ))tan(θ)+cos^2(θ)cot(θ)+2sin(θ)cos(θ)
=tan(θ)-sin(θ)cos(θ)+cos^2(θ)cot(θ)+2sin(θ)cos(θ)
=tan(θ)+cos^2(θ)cot(θ)+sin(θ)cos(θ)
cos^2 = 1 - sin^2 and you are done
 

KingOfActing

lukewarm mess
Joined
Oct 31, 2015
Messages
1,016
Location
Sydney
Gender
Male
HSC
2016
Help:
prove sin^2(θ)tan(θ)+cos^2(θ)cot(θ)+2sin(θ)cos(θ) = tan(θ)+cot(θ)

My working out so far:
LHS=(1-cos^2(θ))tan(θ)+cos^2(θ)cot(θ)+2sin(θ)cos(θ)
=tan(θ)-sin(θ)cos(θ)+cos^2(θ)cot(θ)+2sin(θ)cos(θ)
=tan(θ)+cos^2(θ)cot(θ)+sin(θ)cos(θ)
You're almost there. Continuing on:

 

Green Yoda

Hi Φ
Joined
Mar 28, 2015
Messages
2,859
Gender
Male
HSC
2017
I have the worked our solution and they did some weird shit...
final answer: 3tan(θ)-tan^2(θ)/1-3tan^2(θ)
 
Status
Not open for further replies.

Users Who Are Viewing This Thread (Users: 0, Guests: 3)

Top