Parametric locus question (1 Viewer)

[enigma_1]

How do you do 12 b? Thanks

 

[Squar3root]

isn't that just a simple factorisation?

 

[enigma_1]

isn't that just a simple factorisation?

No like you have to prove it somehow. You don't just show it, you have to prove something from part "a".. But I dunno what exactly to prove.

 

[Squar3root]

No like you have to prove it somehow. You don't just show it, you have to prove something from part "a".. But I dunno what exactly to prove.

well the normals at p is:
and at q is:
[simple derivations]

i was thinking solving them simataneoulsy or something, but that got me nowhere

EDIT: thats all i got lol, soz

 

[enigma_1]

well the normals at p is:
and at q is:
[simple derivations]

i was thinking solving them simataneoulsy or something, but that got me nowhere

EDIT: thats all i got lol, soz

that's okay. Ok now I feel like an idiot, I think I'm overthinking it haha

 

[Squar3root]

that's okay. Ok now I feel like an idiot, I think I'm overthinking it haha

i doubt something like this would be asked in the HSC

 

[enigma_1]

Lol I so hope

 

[enigma_1]

This is a bit better, how do you do part d?

 

[RealiseNothing]

Part a) and b) are not linked.

 

[Drongoski]

isn't that just a simple factorisation?

It is. That is a well-known identity, and it doesn't matter whether or not p & q have anything to do with a parabola.

 

[enigma_1]

It is. That is a well-known identity, and doesn't matter whether or not p & q have anything to do with a parabola.

Hmm ok, thank you.

How do I do part d? Thanks

 

[RealiseNothing]

Let in the co-ordinates from c)

Now you'll get the co-ordinates in the form and where

So it lies on the parabola.

 

[enigma_1]

How do you know t = p + q?

 

[braintic]

How do you know t = p + q?

You don't know that t=p+q. She (he?) is saying that the answer you will get after doing the algebra is [2a(p+q), a(p+q)^2].
Its then up to you to recognise that this is in the standard parametric form for a parabola: , where (in this case) .

 

[RealiseNothing]

She (he?)

You know too much.

 

[enigma_1]

LOOOOOL, ok thank you people

 

[joelferns27]

i had trouble with the exact same question, you must know that part b is independent of part a ! ahaha thats what got me too