Login

Welcome, Guest. Please login or register.

March 28, 2024, 11:52:55 pm

Author Topic: Mathematics Question Thread  (Read 1296714 times)  Share 

0 Members and 13 Guests are viewing this topic.

:3

  • Forum Regular
  • **
  • Posts: 66
  • (─‿‿─)(─‿‿─)(─‿‿─)
  • Respect: 0
Re: Mathematics Question Thread
« Reply #750 on: October 21, 2016, 12:11:40 am »
0
Thanks and sorry Rui and Rikahs,
My mind totally blanked out (probably because its geometry + late at night).

RuiAce

  • ATAR Notes Lecturer
  • Honorary Moderator
  • Great Wonder of ATAR Notes
  • *******
  • Posts: 8814
  • "All models are wrong, but some are useful."
  • Respect: +2575
Re: Mathematics Question Thread
« Reply #751 on: October 21, 2016, 12:17:35 am »
+1
It's past midnight. Time to get a good night sleep

Hua Fei

  • Trailblazer
  • *
  • Posts: 48
  • Respect: 0
Re: Mathematics Question Thread
« Reply #752 on: October 21, 2016, 12:27:10 am »
0
Hi there!

I don't understand how to do these questions:
1) the answer is 4.5. I don't even know how to approach this...
2) the answer is 2. Wouldn't it be 3? Sin gives us one solution and tan gives us the 2nd?

Thank you so much in advance!

RuiAce

  • ATAR Notes Lecturer
  • Honorary Moderator
  • Great Wonder of ATAR Notes
  • *******
  • Posts: 8814
  • "All models are wrong, but some are useful."
  • Respect: +2575
Re: Mathematics Question Thread
« Reply #753 on: October 21, 2016, 12:39:30 am »
0
Hi there!

I don't understand how to do these questions:
1) the answer is 4.5. I don't even know how to approach this...
2) the answer is 2. Wouldn't it be 3? Sin gives us one solution and tan gives us the 2nd?

Thank you so much in advance!
Addressed in post #464
Addressed in post #620
« Last Edit: October 21, 2016, 12:42:40 am by RuiAce »

Hua Fei

  • Trailblazer
  • *
  • Posts: 48
  • Respect: 0
Re: Mathematics Question Thread
« Reply #754 on: October 21, 2016, 12:44:40 am »
0

nibblez16

  • Forum Regular
  • **
  • Posts: 75
  • Respect: 0
  • School: Liverpool Girls
  • School Grad Year: 2016
Re: Mathematics Question Thread
« Reply #755 on: October 21, 2016, 01:04:51 am »
0
Help please last part

RuiAce

  • ATAR Notes Lecturer
  • Honorary Moderator
  • Great Wonder of ATAR Notes
  • *******
  • Posts: 8814
  • "All models are wrong, but some are useful."
  • Respect: +2575
Re: Mathematics Question Thread
« Reply #756 on: October 21, 2016, 01:08:53 am »
0
« Last Edit: October 21, 2016, 05:00:14 am by RuiAce »

nibblez16

  • Forum Regular
  • **
  • Posts: 75
  • Respect: 0
  • School: Liverpool Girls
  • School Grad Year: 2016
Re: Mathematics Question Thread
« Reply #757 on: October 21, 2016, 06:37:03 am »
0
Good Morning :)
For a question like (iii) we have to differentiate, so can be times the power 'k' with the whole number? In this case k= 0.0347 (4dp) but the whole number is 0.03465735903
Can we times it with the whole number? because the answer multplies it with only 4dp....

jamonwindeyer

  • Honorary Moderator
  • Great Wonder of ATAR Notes
  • *******
  • Posts: 10150
  • The lurker from the north.
  • Respect: +3108
Re: Mathematics Question Thread
« Reply #758 on: October 21, 2016, 08:03:19 am »
0
Good Morning :)
For a question like (iii) we have to differentiate, so can be times the power 'k' with the whole number? In this case k= 0.0347 (4dp) but the whole number is 0.03465735903
Can we times it with the whole number? because the answer multplies it with only 4dp....

Morning! You would be paid for either, but as a rule of thumb, if you find a rounded value in an earlier part of the question, carry it through the rest of the questions! It is cleaner and still yields the required level of accuracy ;D

nibblez16

  • Forum Regular
  • **
  • Posts: 75
  • Respect: 0
  • School: Liverpool Girls
  • School Grad Year: 2016
Re: Mathematics Question Thread
« Reply #759 on: October 21, 2016, 08:34:58 am »
0
Morning! You would be paid for either, but as a rule of thumb, if you find a rounded value in an earlier part of the question, carry it through the rest of the questions! It is cleaner and still yields the required level of accuracy ;D

Okay Thanks!

nibblez16

  • Forum Regular
  • **
  • Posts: 75
  • Respect: 0
  • School: Liverpool Girls
  • School Grad Year: 2016
Re: Mathematics Question Thread
« Reply #760 on: October 21, 2016, 08:36:35 am »
0
How do we know when to use a discriminant and which one to use (>, <, =)

zemilyx

  • Adventurer
  • *
  • Posts: 12
  • Respect: 0
  • School: Trinity Catholic College
  • School Grad Year: 2017
Re: Mathematics Question Thread
« Reply #761 on: October 21, 2016, 09:07:26 am »
0
hi
with this time payment question, I don't understand why the expression for A1 ends up as Px1.04^7+5000 instead of Px1.04^8 +5000. Is there a general rule for working out the time period in time repayment questions where they don't just state over a period of n years but rather say between this year and that year etc because to me it seems the answer varies between different questions and I don't know why.
Thanks :))

BPunjabi

  • Forum Obsessive
  • ***
  • Posts: 262
  • So... Hows life?
  • Respect: 0
Re: Mathematics Question Thread
« Reply #762 on: October 21, 2016, 09:09:43 am »
0
hi
with this time payment question, I don't understand why the expression for A1 ends up as Px1.04^7+5000 instead of Px1.04^8 +5000. Is there a general rule for working out the time period in time repayment questions where they don't just state over a period of n years but rather say between this year and that year etc because to me it seems the answer varies between different questions and I don't know why.
Thanks :))

Its too late now, dont worry just wing it!
Did HSC in 2016 and was first person to get 100. Aeronautical engineering for me now :P
  <-- CLICK ME

BPunjabi

  • Forum Obsessive
  • ***
  • Posts: 262
  • So... Hows life?
  • Respect: 0
Re: Mathematics Question Thread
« Reply #763 on: October 21, 2016, 09:13:21 am »
0
How do we know when to use a discriminant and which one to use (>, <, =)

Its too late now just wing it  ;D.

But here:

1. if triangle is <0, roots are real, rational and equal
2. If triangle is =0 roots are unreal and unrational
3. If triangle is >0 roots are unreal, irrational and unequal
Did HSC in 2016 and was first person to get 100. Aeronautical engineering for me now :P
  <-- CLICK ME

WLalex

  • Forum Regular
  • **
  • Posts: 64
  • Respect: 0
Re: Mathematics Question Thread
« Reply #764 on: October 21, 2016, 09:13:32 am »
0
hi
with this time payment question, I don't understand why the expression for A1 ends up as Px1.04^7+5000 instead of Px1.04^8 +5000. Is there a general rule for working out the time period in time repayment questions where they don't just state over a period of n years but rather say between this year and that year etc because to me it seems the answer varies between different questions and I don't know why.
Thanks :))

Do not count 2007 for interest as the 5000 is deposited at the beginning therefore the P is only gaining interest until 2006 e.g. 7 times not 8 (8 would be at the end of 2007)
"You don't want to look back and know you could have done better"

2016: Advanced English, Mathematics , Extension Maths, Chemistry, SOR II, PDHPE

ATAR: 97.70