Specialist 1/2 Question Thread!

[Helish]

I am not interested in bio, and my physics teacher has given me chapters to do from 1&2 physics which require the prior knowledge for 3&4, I am also in an advance maths class and currently receiving

There are many factors that need to be taken into account. For example:
- Do you feel like Spec is right for you? I mean, are you capable of handling methods and spesh? If you feel like you enjoy maths in general and you are willing to put in enough hard work (I had to anyway) then from what I know you should be fine.
- You said you wanted to do medicine right, then have you ever thought of doing bio?
- Are specialist and/or prerequisites for your aspiring university course?
As for Physics units 3/4 without 1/2, I can't say much, but from what I know if you have enough determination it is possible to do it. But let me just warn you that you will be at a disadvantage (depends on your school as well tho), as some concepts of physics units 3/4 (like for example my textbook relies on prior knowledge to study the concepts like magnetic flux and stuff), but DW, the disadvantage is not relatively large.

Hey, guys, I am currently in year 10 doing 1 and 2 business management. next year I am hoping to do eng 1&2 methodes1&2 chem1&2 business management 3&4 and specialist 1&2. I also want to do physics so I thought after I complete Business management, in year 12 I'll do physics 3&4 without 1&2. But teachers said that really hard, so now I am confused in doing physics 1&2 in year 11 and not do spec at all. Is it worth it or not. In my career I want to do medicine or astrophysicist, I really need help guys.

above 90, but also do I require Bio knowledge to pass the UCAT

[^^^111^^^]

I am not interested in bio, and my physics teacher has given me chapters to do from 1&2 physics which require the prior knowledge for 3&4, I am also in an advance maths class and currently receiving above 90, but also do I require Bio knowledge to pass the UCAT

Well if your physics teacher is giving you those chapters then I guess you should be fine. From what I can see, you should be able to easily survive a spesh class as well. As for UCAT, most likely not since UCAT should just be an aptitude test, but I would recommend bio bcos u said your career could be surrounding medicine as well. That's up to you anyway, since you also have chemistry as a VCE subject and given that you pursue it to units 3/4.

[Helish]

Thanks

Well if your physics teacher is giving you those chapters then I guess you should be fine. From what I can see, you should be able to easily survive a spesh class as well. As for UCAT, most likely not since UCAT should just be an aptitude test, but I would recommend bio bcos u said your career could be surrounding medicine as well. That's up to you anyway, since you also have chemistry as a VCE subject and given that you pursue it to units 3/4.

man for building up my willpower and helping me decide my subjects, I'll try my best to achieve the highest atar possible, Thanks again

[caffinatedloz]

Thanks man for building up my willpower and helping me decide my subjects, I'll try my best to achieve the highest atar possible, Thanks again

Great attitude! Best of luck!

[ArtyDreams]

Hey! Am doing further trigonmetry from the Cambridge textbook and am really stuck on proofs (I'm horrible at them!)

Can anyone possibly help me prove this identity?
sec (x) + cosec (x) cot (x) = sec (x) cosec^2 (x)

Also, when doing proofs llike this, do we tackle them as a show that question? Whats the best place to start?

I'd really appreciate any help.
Thanks!!! 

[S_R_K]

Hey! Am doing further trigonmetry from the Cambridge textbook and am really stuck on proofs (I'm horrible at them!)

Can anyone possibly help me prove this identity?
sec (x) + cosec (x) cot (x) = sec (x) cosec^2 (x)

Also, when doing proofs llike this, do we tackle them as a show that question? Whats the best place to start?

I'd really appreciate any help.
Thanks!!! 

Yes, a "show that" question is essentially asking you to give a proof.

For trig-identity questions like this, you generally have three methods. (1) Start with the LHS, and show, using legitimate steps, that it is equal to the RHS; (2) Start with the RHS and show, using legitimate steps, that it is equal to the LHS; (3) Work with both sides independently and show that they are each equal to some other expression. There is no foolproof method for knowing which is best in any given case. Improvement requires experience and practice; with that comes good judgement and intuition for how to get started.

For the question you've given, my first instinct is to multiply the LHS by cos(x), because that gives 1 + cot^2(x). That's useful, because I also know (from Pythgoras) that 1 + cot^2(x) = cosec^2(x). So, working backwards, now I consider what happens when I start with 1 + cot^2(x) = cosec^2(x), and divide both sides by cos(x)...

[ArtyDreams]

Yes, a "show that" question is essentially asking you to give a proof.

For trig-identity questions like this, you generally have three methods. (1) Start with the LHS, and show, using legitimate steps, that it is equal to the RHS; (2) Start with the RHS and show, using legitimate steps, that it is equal to the LHS; (3) Work with both sides independently and show that they are each equal to some other expression. There is no foolproof method for knowing which is best in any given case. Improvement requires experience and practice; with that comes good judgement and intuition for how to get started.

For the question you've given, my first instinct is to multiply the LHS by cos(x), because that gives 1 + cot^2(x). That's useful, because I also know (from Pythgoras) that 1 + cot^2(x) = cosec^2(x). So, working backwards, now I consider what happens when I start with 1 + cot^2(x) = cosec^2(x), and divide both sides by cos(x)...

Thank you so so much for answering - I really appreciate it! Your answer was really helpful. I do understand it a bit more now - just need to do more practice

[Evolio]

Let a be the magnitude of acceleration of each mass; let T be the tension in the string. Writing an equation of motion (ie. using F = ma) for each mass we have:

1: 50a = T
2: 20a = 20g – T.

Adding equations gives 70a = 20g, so the acceleration of each mass is 2g/7. Hence the speed of each mass is 2gt/7, where t is in seconds.

Thank you so much, S_R_K!
 

[radiant roses]

Hello,
Can I please have some help with question (b)
I attempted the question by making 3 cases:

1) x is less than or equal to 5/2
I got x = -9

2) x is greater than or equal to 4
I got x=11

3) x is between 5/2 and 4.
For this case, I got x=19/3 but the answers only say x=-9 and x=11
Why is this the case?

[S_R_K]

Hello,
Can I please have some help with question (b)
I attempted the question by making 3 cases:

1) x is less than or equal to 5/2
I got x = -9

2) x is greater than or equal to 4
I got x=11

3) x is between 5/2 and 4.
For this case, I got x=19/3 but the answers only say x=-9 and x=11
Why is this the case?

The answer is in your working out. x = 19/3 is not in the interval 5/2 < x < 4. It's a spurious solution that arises because of the way you remove the modulus signs to obtain a linear equation.

[JimDADDY2009]

Hello everyone I am in year 9, and I have a question if you could help me answer it please thnx

The mathematician George enjoyed telling his friends he was x years old in the year x². Find the year of Georges birth given he died in 1871 (rip George) 

[keltingmeith]

Hello everyone I am in year 9, and I have a question if you could help me answer it please thnx

The mathematician George enjoyed telling his friends he was x years old in the year x². Find the year of Georges birth given he died in 1871 (rip George) 

(note: what you're about to see is my full approach at tackling the problem. This is to illustrate how I might approach this problem, which is far more valuable than me just giving you the answer)

So, we need to find a number such that when squared, it gives a number less than 1871. What's a number that's less than 1871? Well, 1871-y is. So, let's set up that first equation:

1871-y=x

Now, let's apply some logic. While we don't know what age George died at, in the 19th century, you weren't going to live for a hell of a long time - so let's just say he couldn't have been born before 1800. This gives us some room to work with.

And this is where I'm not sure what my next logical step would be - so, let's try playing around. What are the list of squares that'll get you between 1800 and 1871?

10^2=100
20^2=400
30^2=900
40^2=1600
45^2=2025

Too far, let's go back

42^2=1764
43^2=1849
44^2=1936

Brilliant, there's only one age that fits - being 43 in 1849.

Since 1849-43=1806, we can say our good pal' George was born in 1806, living to ripe old age of 65.

[ErnieTheBirdi]

Can someone please help me with this question, I don't really understand how to do it even after looking at the worked solutions. If a, 4a - 4 and 8a - 13 are successive terms of an arithmetic sequence, find a. Thankyou in advance

[RuiAce]

Can someone please help me with this question, I don't really understand how to do it even after looking at the worked solutions. If a, 4a - 4 and 8a - 13 are successive terms of an arithmetic sequence, find a. Thankyou in advance

In an arithmetic terms, successive terms must have the same common difference.

That means, the difference between the second and first term, should equal the difference between the third and second term.

So we end up with the equation
\[ (4a-4) - a = (8a-13) - (4a-4). \]
The solution to this equation is \(a=5\).

[ErnieTheBirdi]

Could someone help me with this question? For the sequence 4, 8, 12, ... , find:
a) the sum of the first 9 terms
b) {n : Sn} = 180

mainly part B

P.S thank you to the lecturer who helped me with the previous question I had