VCE Specialist 3/4 Question Thread!

[soccerboi]

substitute the from 5(c)(i) and stated in the question, simplify and eventually, it simplifies to and thus, satisfies the differential equation.

yeah, that's what you do to show it satisfies the condition

Yes but they replaced x(t) with (x/1+t) which is what is confusing me. Why did they do this?

[polar]

they substitute x(t) where the x was and that's why the denominator is instead of

[soccerboi]

they substitute x(t) where the x was and that's why the denominator is instead of

oooohhh!! Thanks so much!!! Finally i understand it

[WhoTookMyUsername]

Anyway to convert a parametric Equation to a cartesian equation on cas?

I know of a way with the Classpad, but I don't think there's a way with the nSpire.

You could do it on tiinspire before a recent update, just by typing in and pressing solve, but you can't do that anymore
Also is piSx^2dy
An acceptable line of notation? As your not integrating with respect to x, but with respect to y?

[pi]

It's probably not the best notation for VCAA exams (even though I used it in my own notes etc.) unless you define x=... first. Play it safe imo.

[Biceps]

i do parametric equations by hand and if that isn't possible then i just use the parametric equations as they are. You can sketch them on a ti now btw.

[rife168]

Anyway to convert a parametric Equation to a cartesian equation on cas?

I know of a way with the Classpad, but I don't think there's a way with the nSpire.

How do you do it with the Classpad?

[supermanflyaway]

Please explain VCAA 2007 4.c) and 2011 MC 18 (why find x2).

[Biceps]

for 4) c) get the velocity vector then you use tan inverse to come up with the angle.
MC 18) it says scalar resolute in the direction of u so you find u unit vector and then get the dot product with v and then you make it equal to 1 and so a=3/2

[supermanflyaway]

for 4) c) get the velocity vector then you use tan inverse to come up with the angle.
MC 18) it says scalar resolute in the direction of u so you find u unit vector and then get the dot product with v and then you make it equal to 1 and so a=3/2

What values do you use tan inverse on?

Sorry, it was 2011 MC

[Biceps]

k value over the value of the line between i and j (use pythagoras theorem).

[Biceps]

as for MC 2011 question 18 all you have to do is eulers formula but you use x as your y and t as your usual x.

[Wingtips]

Vcaa 2011 2d.ii

How is z=x+ix?

I worked it out with something like
Re(z)=Im(z)
And subbed in values to get the required line.

[Lasercookie]

Vcaa 2011 2d.ii

How is z=x+ix?

I worked it out with something like
Re(z)=Im(z)
And subbed in values to get the required line.

You did pretty much the same thing, instead you used the values as Re(z) = Im(z). Since z = x + yi, Re(z) = x, Im(z) = y

So we want to express the line y = x in the form



sub in y = x


and so on

[zvezda]

Use the double angle formula for tan2x, and the fact that tan(pi/4)=1, to find the exact value of tan(pi/8).
Having a bit of trouble with this one; how would I go about doing this?