VCE Specialist 3/4 Question Thread!

[Jeggz]

How are we all feeling about tomorrow? 

[papertowns]

help please

[sin0001]

help please

Consider tan^-1 (piT/6), it approaches pi/2 as t-->infinity
So 17tan^-1 (piT/6) would be 'stretched' by a factor of 17 from the x-axis, and therefore its max. range will be 17pi/2, as T--> infinity

[Stevensmay]

help please

Best to do this by simplifying it.
We know that the range of will be
This is on your formula sheet if you forget.

If we graph this, we can see that no matter how big x gets, the y value will never reach
We simply times this by 17, as that was the amplitude of the original graph to get 

Therefore the terminal velocity is , as no matter how long it accelerates it will never reach this velocity.

[papertowns]

Thank you both! Makes sense

[papertowns]

I've shaded the region, just not sure how to work out the area

[Stevensmay]

I've shaded the region, just not sure how to work out the area

Was z defined as something? Need a bit more info to work out the best approach.

[papertowns]

Was z defined as something? Need a bit more info to work out the best approach.

Woops yes sorry haha, z was cis(pi/12) and z^4 = cis(pi/3)

[papertowns]

that's for z1 btw

[Stevensmay]

I've shaded the region, just not sure how to work out the area

Most simplest approach is thus.

The angle of the area we are interested in is

We are going to calculate the area of a circle with radius 2, then subtract the area of a circle with radius 1.

Area of a circle is normally but we only have of a circle, or 1/8 of the area, .

Let r = 2.


So now we need to find the area of the smaller circle, so we can subtract it away.
Let r = 1


Therefore total area will be the larger circle subtract the smaller circle.



There are more complex methods but I prefer this one.

[papertowns]

Most simplest approach is thus.

The angle of the area we are interested in is

We are going to calculate the area of a circle with radius 2, then subtract the area of a circle with radius 1.

Area of a circle is normally but we only have of a circle, or 1/8 of the area, .

Let r = 2.


So now we need to find the area of the smaller circle, so we can subtract it away.
Let r = 1


Therefore total area will be the larger circle subtract the smaller circle.



There are more complex methods but I prefer this one.

Thank you so much!! Was really confused with the 1/8 in the assessor's report but this all makes sense now thank you again!

[barydos]

Guys I'm derping out badly.
How do you convert z=iz to cartesian form
x+yi = i(x+yi)
x+yi = -y + xi
x = - y ?
or y = x ?

what do i do

[abcdqd]

Guys I'm derping out badly.
How do you convert z=iz to cartesian form
x+yi = i(x+yi)
x+yi = -y + xi
x = - y ?
or y = x ?

what do i do

I don't think that exists? Or the only solution is (0,0)? You might be thinking of z=i*conj(z)

[barydos]

I don't think that exists? Or the only solution is (0,0)? You might be thinking of z=i*conj(z)

Wow that's supremely awkward, the questions says z=i*conj(z) you're right. I just wasn't reading right haha.
Now I can have peace of mind thanks to you. CHEERS!

[ahat]

"If force ai + bj and ci + dj newtons act simultaneously on an object of m kg, it's acceleration in ms^-2 will be?
If the question wanted us to find the magnitude of the acceleration, would it explicitly say "magnitude of acceleration"? (as the answer to the above question is a vector) Thanks.

Also, for this question, which answer would you choose?

Spoiler