VCE Specialist 3/4 Question Thread!

[blacksanta62]

Hey guys, this is something that is bugging me and it might be a conceptual misunderstanding. Why is it that we take out a 1/2 as a factor? I thought that we only did that the make the numerator and the value of a the same (but if the numerator was one, then that wasn't needed). So I ended up getting:
x = tan^-1(y + 2/2) +c
and y(0) = 0 ===> c = -pi/4

If anyone could tell me why my way of thinking resulted in a wrong answer and how I should go on about these questions in the future, that would be greatly appreciated

Any help would be appreciated

[Sine]

Any help would be appreciated

Take out the 1/2 factor as you require a 2 in the numerator to use the integration rule  as per the formula sheet.

You could also do it intuitively thinking, i have 1 of the 2 required so it's half whatever the resulting expression is.

[blacksanta62]

Take out the 1/2 factor as you require a 2 in the numerator to use the integration rule  as per the formula sheet.

You could also do it intuitively thinking, i have 1 of the 2 required so it's half whatever the resulting expression is.

Even if the numerator is one?

Edit:

If you want harder integrals, google 'difficult integrals'. I legit did that one day and the integrals I got weren't easy. Try http://www.physicsforums.com/showpost.php?p=3433157&postcount=272 for instance.

Can the harder ones be done by hand? They look like they could be very useful for practice. Even the 'easy' ones are

[Sine]

Even if the numerator is one?

Yes the 2 is needed since you have a 4 in the denominator.

The integration rule shows that the numerator is square root of the constant term in the denominator

[blacksanta62]

Can anyone help me with this, I keep getting an incorrect answer.
Thank you
Edit: It's about separation of variables

[zsteve]

Can anyone help me with this, I keep getting an incorrect answer.
Thank you
Edit: It's about separation of variables

[lzxnl]

Even if the numerator is one?

Edit:Can the harder ones be done by hand? They look like they could be very useful for practice. Even the 'easy' ones are

I haven't looked at all of them yet, and I'm fairly sure I can't even do all of them myself.

[blacksanta62]

Hey, two questions:
1) Why did they multiply everything by ten? Is this necessary?
2) If I was to stop and not multiply by ten but replace V with 6pih, would I be wrong?
Thank you

[Sine]

Hey, two questions:
1) Why did they multiply everything by ten? Is this necessary?
2) If I was to stop and not multiply by ten but replace V with 6pih, would I be wrong?
Thank you

1) They didn't multiply everything by 10 , note 1/6pi is divided by 10 becoming 1/60pi, they simplified the decimals into whole numbers, you don't really have to remove decimals(if they are exact e.g 1/2 = 0.5) but it looks neater without them.
2)Yep still correct (full marks) but again in general it looks neater without the decimals 

[blacksanta62]

1) They didn't multiply everything by 10 , note 1/6pi is divided by 10 becoming 1/60pi, they simplified the decimals into whole numbers, you don't really have to remove decimals(if they are exact e.g 1/2 = 0.5) but it looks neater without them.
2)Yep still correct (full marks) but again in general it looks neater without the decimals 

Thanks sine

[Jakeybaby]

Hey,

 I was just wondering, in my investigation that I am currently completing on Bezier Curves, this question is apparent:

Draw the curve with labelled points etc. On the same graph, draw in the line segments SC1 & C2E. Comment on the relationship between these lines and the Bezier Curve.

It is obvious that they are tangential to the curve, but what else could be said about the relationship? I feel like there are other aspects of the relationship which I am ignoring.

[blacksanta62]

Hey guys, just really confused with a certain aspect of this question (part d.i):
1) isn't AB = AO + OB
                 = -(3i + 2j +sqrt3 k) + 4i
                 = i -2j - sqrt3 k
Therefore OQ = 1/2 (AB)

Why is AO positive giving us 7/2?
Thank you

[Syndicate]

Hey guys, just really confused with a certain aspect of this question (part d.i):
1) isn't AB = AO + OB
                 = -(3i + 2j +sqrt3 k) + 4i
                 = i -2j - sqrt3 k
Therefore OQ = 1/2 (AB)

Why is AO positive giving us 7/2?
Thank you

OQ = OA + 1/2(AB)

[Apink!]

Could I get urgent help for this question?
Find the cartesian equation of the path of the particle B

[Sine]

Could I get urgent help for this question?
Find the cartesian equation of the path of the particle B

and
therefore cartesian equation is
however 
so domain is