VCE Specialist 3/4 Question Thread!

[brightsky]

oh soz i see what your problem is now; 'tis a dodgy question, because for all real coefficients, the complex roots need to be conjugates of one another.

[ashs_vb]

if cos^2(x) + sin^2(x)=1
then   cos^2(x) + sin^2(x)= 1.(cos^2(x) + sin^2(x))
                                          = {cos^2(x) + sin^2(x)}.{cos^2(x) + sin^2(x)}
hence cos^2(x) + sin^2(x)= {cos^2(x) + sin^2(x)}^n    N is an element of R

Is this correct?
Just wondering

[Jayward]

if cos^2(x) + sin^2(x)=1
then   cos^2(x) + sin^2(x)= 1.(cos^2(x) + sin^2(x))
                                          = {cos^2(x) + sin^2(x)}.{cos^2(x) + sin^2(x)}
hence cos^2(x) + sin^2(x)= {cos^2(x) + sin^2(x)}^n    N is an element of R

Is this correct?
Just wondering

Yeap

What about this? I know this is pretty dumb, but am having a serious mental blank. Im pretty sure that Im right, but i just wanted to make sure

[Conic]

Yeap

What about this? I know this is pretty dumb, but am having a serious mental blank. Im pretty sure that Im right, but i just wanted to make sure

Its , since

A little more info:

Let

then

Now from pythagoras' theorem:

[Jayward]

Its , since

thanks! serious mental blankness! I shouldve remembered that you take out i when you determine the modulus! hahahah

[jono88]

If z=2icis(θ)-1/2icis(- θ)
Show that z lies on the ellipse with equation y^2/25 + x^2/9=1/4

I solved everything into x and y components, simplified and got x^2/25 + y^2/9=1/4 instead. :/

[Hancock]

If z=2icis(θ)-1/2icis(- θ)
Show that z lies on the ellipse with equation y^2/25 + x^2/9=1/4

I solved everything into x and y components, simplified and got x^2/25 + y^2/9=1/4 instead. :/

Wut?

[jono88]

^YES I GOT THE EXACT SAME THING

[jono88]

well w=2i cis(theta) and z=w- w^-1

unless z = 2i*cis*\theta - \frac{1}{2i}*cis(-\theta) ?

[Hancock]

well w=2i cis(theta) and z=w- w^-1

unless z = 2i*cis*\theta - \frac{1}{2i}*cis(-\theta) ?

I read your question as

[jono88]

z=w-(1/w)

[Will T]

Question 3b. Essentials Exercise 2D. Help please.

[Nobby]

Question 3b. Essentials Exercise 2D. Help please.

Find the unit vector of the vector that bisects the line from A to B.

[saba.ay]

Can someone pleasedo question 2b maths quest chapter 1 review extended response. I need the working out. I get y=2x + 4/(x(1-x) but the answer is y=2x + 4/(x(1-4)).

??

Please and thanks

[Jayward]

What would this graph look like? I have no clue. I vaguely think its a circle, but am not entirely sure