VCE Specialist 3/4 Question Thread!

[keltingmeith]

Another question, when it says find an anti-derivative do we use c?
In Itute, they don't use it and in some VCAA papers they do and they dont, there not consistent

From the 'Stupid' Exam Questions thread:

Do I have to include my "+c" when I integrate?
If it's a definite integral, of course not.
If the question says "find AN antiderivative", you can include it, but you don't need to (I'd suggest not including it).
If the question just says "antidifferentiate f(x)" or "Find ", you HAVE to include it or your final answer is wrong.

Recently, VCAA has been following this trend in both methods and specialist exams.

[speedy]

Could someone explain this question to me? And why was every answer marked as correct?

Spoiler

[lzxnl]

Could someone explain this question to me? And why was every answer marked as correct?

Spoiler

Well...of course, none of them are correct because if it says z^3, you should have three different intervals for the argument
Second quadrant means (pi/2, pi)
So one possibility is (pi/6, pi/3). But you can add 2pi/3 to this. And again to get three different intervals. The answers don't have that option so...everything there is wrong

[speedy]

Well...of course, none of them are correct because if it says z^3, you should have three different intervals for the argument
Second quadrant means (pi/2, pi)
So one possibility is (pi/6, pi/3). But you can add 2pi/3 to this. And again to get three different intervals. The answers don't have that option so...everything there is wrong

Oh lol... But is there any way of knowing for certain where the argument will lie between? Or do you just know that there will be three regions, thus  the correct answer would be anything with three sets that logically works, ie. spaced correctly?

Edit: Dw, I think I get it, you are dividing (pi/2,pi) by 3 right?

Also, when do we include the open circle at the origin? Is it only when sketching rays?

[lzxnl]

Oh lol... But is there any way of knowing for certain where the argument will lie between? Or do you just know that there will be three regions, thus  the correct answer would be anything with three sets that logically works, ie. spaced correctly?

Edit: Dw, I think I get it, you are dividing (pi/2,pi) by 3 right?

Also, when do we include the open circle at the origin? Is it only when sketching rays?

More like...anything with three intervals that have the correct numbers.

As for your second question, don't rote learn this. Think about it. If the question asks you to sketch Arg(z) = pi, well the argument of zero isn't defined. THAT's why you have an open circle. The Arg function isn't defined at 0.

[Valyria]

Could someone please tell me the CAS syntax for euler's method?

Secondly, if we say z=1+i would:

[lzxnl]

Could someone please tell me the CAS syntax for euler's method?

Secondly, if we say z=1+i would:

For the first question: I've used it as a spreadsheet. I don't know if the CAS does Euler's method in a program (it might)

For the second one, in the complex numbers the square root is a little tricky to define. However, square root means 'one' of the possible square roots. 'The square root' of 1 + i is simply sqrt2*cis(pi/4). The plus-minus and the +2k*pi are redundant.
For the general solution, you don't need the plus-minus in front of the sqrt 2

[keltingmeith]

For the first question: I've used it as a spreadsheet. I don't know if the CAS does Euler's method in a program (it might)

There isn't a program on the calculator, but with a bit of programming knowledge it's not hard to write one up. There might also be one in the package I put up on AN months ago, if anybody wants me to go dig it up?

[psyxwar]

There isn't a program on the calculator, but with a bit of programming knowledge it's not hard to write one up. There might also be one in the package I put up on AN months ago, if anybody wants me to go dig it up?

TI nspire can do eulers.

Its eulers(dy/dx,x,y,{x0,xn},y0,h) if memory serves me right, but you can probably google this. You can also do it graphically through the differential equation graphing bit, which you can google a video of

[keltingmeith]

TI nspire can do eulers.

Its eulers(dy/dx,x,y,{x0,xn},y0,h) if memory serves me right, but you can probably google this. You can also do it graphically through the differential equation graphing bit, which you can google a video of

Welp, this is new, then. Didn't have this fancy thing when I did year 12, hahah.

[speedy]

TI nspire can do eulers.

Its eulers(dy/dx,x,y,{x0,xn},y0,h) if memory serves me right, but you can probably google this. You can also do it graphically through the differential equation graphing bit, which you can google a video of

FFS, I keep seeing more and more of these handy functions that we don't have on the CASIO, makes me wish I had gotten the TI

Edit:

Does this imply answers with g in them wouldn't be given full marks?

Spoiler

[lolalol]

Edit:

Does this imply answers with g in them wouldn't be given full marks?

Spoiler

If it gives g=9.8 in the question then that probably implies that we need to use it

[lolalol]

Hi guys, could somebody please explain why the two integrals are equal in the solution to this question? Thanks in advance!

[speedy]

If it gives g=9.8 in the question then that probably implies that we need to use it

OMG I'm an idiot, it asks for "correct to the nearest Newton" :/

[keltingmeith]

Hi guys, could somebody please explain why the two integrals are equal in the solution to this question? Thanks in advance!

It's because they're solving the differential equation by a separation of variables - if you don't know what it is, ignore it, and solve the differential equation with