Help In Understanding. (1 Viewer)

[Shadowless]

Question:

Answer:

I don't understand why.

I've realised that when I did this problem I did what the solution required of me (i.e. using quadratics and using the discriminant, etc, etc. because the question prior to this set me up a quadratic obviously) but I've never understood why.

Could someone explain this solution to me?

EDIT: PART TWO OF THE QUESTION NOT PART ONE.

 

[Nws m8]

product of ratio of intercepts brah

 

[Shadowless]

product of ratio of intercepts brah

I meant part two. I get part one. Sorry about the misunderstanding. =S

 

[HeroicPandas]

If "x" is a length then it must be REAL, to find real roots we use DELTA greater or equal to zero

Taking the equality of the inequality for the min distance

 

[Nws m8]

If "x" is a length then it must be REAL, to find real roots we use DELTA greater or equal to zero

Taking the equality of the inequality for the min distance

pretty much this

 

[HeroicPandas]

We can't have unreal "x" values because we are looking at LENGTHS, since we don't know how many VALUES of "x", we use DELTA is greater or equal to zero

We cant use DELTA greater than zero

^ I think i just confused myself

 

[HeroicPandas]

Do u get it?

 

[Shadowless]

Hmm. Okay. I get it now. Thanks.

Next...

Question:

Answer:

My question is, let's say once we find 'x' can we just do the following?

As x = ???, subbing this value into equation 1 will yield y = ??? (we know the value for y as this is a show question and they already gave it to us).

Then write...

Therefore the coordinate of point R is (X,Y) [by looking at the question].

 

[HeroicPandas]

Hmm. Okay. I get it now. Thanks.

Next...

Question: View attachment 26807

Answer: View attachment 26808

My question is, let's say once we find 'x' can we just do the following?

As x = ???, subbing this value into equation 1 will yield y = ??? (we know the value for y as this is a show question and they already gave it to us).

Thats risky, I wouldn't do that xD
Just work it out

 

[HeroicPandas]

Hmm. Okay. I get it now. Thanks.
[by looking at the question].

Do u get the first question 100%?

 

[Shadowless]

Thats risky, I wouldn't do that xD
Just work it out

How is it 'risky'? Will I lose marks?

 

[HeroicPandas]

If u dont entirely get the first question on that circle question, just use calculus, let f(x) be blah blah, differnetiaite equate etc

 

[Nws m8]

Hmm. Okay. I get it now. Thanks.

Next...

Question: View attachment 26807

Answer: View attachment 26808

My question is, let's say once we find 'x' can we just do the following?

As x = ???, subbing this value into equation 1 will yield y = ??? (we know the value for y as this is a show question and they already gave it to us).

Then write...

Therefore the coordinate of point R is (X,Y) [by looking at the question].

SImple question bro, equate two equations and find x and y ....

 

[Shadowless]

If u dont entirely get the first question on that circle question, just use calculus, let f(x) be blah blah, differnetiaite equate etc

LOL that's what I did, but it seemed too much working out compared to the answers, so yeah.

 

[Shadowless]

SImple question bro, equate two equations and find x and y ....

Are you even looking at my 'question'? LMAO

Most of my 'problems' in 3U isn't that I don't know how to solve, it's more 'what's the quickest and most efficient way of doing the question' if you get what I mean.

 

[HeroicPandas]

How is it 'risky'? Will I lose marks?

The question says SHOW that the normals at P and Q intersect at this point, so u have to WORK IT OUT
yeh u will lose marks :\

 

[Nws m8]

Are you even looking at my 'question'? LMAO

Most of my 'problems' in 3U isn't that I don't know how to solve, it's more 'what's the quickest and most efficient way of doing the question' if you get what I mean.

lol that's the way I do it, it is quick ...

 

[HeroicPandas]

LOL that's what I did, but it seemed too much working out compared to the answers, so yeah.

ok lol

 

[Shadowless]

lol that's the way I do it, it is quick ...

You are misunderstanding everything I say LMAO.

 

[Nws m8]

You are misunderstanding everything I say LMAO.

Gangname Style