HSC 2015 MX1 Marathon (archive) (1 Viewer)

[davidgoes4wce]

Re: HSC 2015 3U Marathon

Have learnt this course for nearly 12 months now ( did the prelim for 6 months). My slight weakness is Binomial Theorem and Geometry.

Its not that I haven't practiced enough but I kind of went through 4/5 of the book in Fitzpatrick and did zilch form Margaret Grove in Prelim and HSC texts.

I will make sure I go over Grove and the concepts again in summer.

 

[kawaiipotato]

Re: HSC 2015 3U Marathon

Simplify

 

[davidgoes4wce]

Re: HSC 2015 3U Marathon

I have seen it in books time and time again but never made the effort to memorise that in 1 step. I will do now.

 

[InteGrand]

Re: HSC 2015 3U Marathon

I have seen it in books time and time again but never made the effort to memorise that in 1 step. I will do now.

 

[davidgoes4wce]

Re: HSC 2015 3U Marathon



I understand how angle AFG= angle AOG (angle subtended by the same arc AG)

My question with regards to a cyclic quad, must one of the points go through the centre , O, for a cyclic quad to exist?

 

[Carrotsticks]

Re: HSC 2015 3U Marathon

I understand how angle AFG= angle AOG (angle subtended by the same arc AG)

My question with regards to a cyclic quad, must one of the points go through the centre , O, for a cyclic quad to exist?

Yes.

Also what paper is this from? Looks like Grammar.

 

[davidgoes4wce]

Re: HSC 2015 3U Marathon

Its from Samir El Hosri study guide

 

[davidgoes4wce]

Re: HSC 2015 3U Marathon





This is the solution for part (i)





I wanted to state my reason as: ("The angle is subtended by the same chord AB"). Would this be good enough to get the 1 mark ?

 

[Crisium]

Re: HSC 2015 3U Marathon

I wanted to state my reason as: ("The angle is subtended by the same chord AB"). Would this be good enough to get the 1 mark ?

You have to include the implication of it being subtended by the same chord

It's like saying "co-interior angles in parallel lines" but it excludes whether they're equal, not equal, etc. so be specific and say "co-interior angles in parallel lines are supplementary"

 

[davidgoes4wce]

Re: HSC 2015 3U Marathon





Looking at the question first time, I had no idea where to start. When checking the solutions, I noticed they placed an x^2 term next to the (1+x)^n. When you integrate this coefficient you do see the 1/3 nC0 (which is 1/3) for the first time.

My question is in past HSC or other papers must we be able to spot the integration coefficients by inspection? I for one know the integrated value of x^2 = is x^3/3 and when you substitute a value of x=1 or x=-1 you can determine the sign whether it be positive or negative.

 

[davidgoes4wce]

Re: HSC 2015 3U Marathon

I'm going to get some spaghetti Bolognaise after spending time doing Binomials

 

[dathat]

Re: HSC 2015 3U Marathon

I understand how angle AFG= angle AOG (angle subtended by the same arc AG)

My question with regards to a cyclic quad, must one of the points go through the centre , O, for a cyclic quad to exist?

how do you prove the cyclic quad??
as far as i could get is angle AOG=CAB=DAG and i dont know where to from that?

 

[Drsoccerball]

Re: HSC 2015 3U Marathon

how do you prove the cyclic quad??
as far as i could get is angle AOG=CAB=DAG and i dont know where to from that?

Angles at center are two times angle at circumference and angles in triangle and straight line add up to 180 degrees. Therefore cycli(angles in same segment) ceebs doing it look for what I did lel

 

[thomasdo1]

Re: HSC 2015 3U Marathon

Looking at the question first time, I had no idea where to start. When checking the solutions, I noticed they placed an x^2 term next to the (1+x)^n. When you integrate this coefficient you do see the 1/3 nC0 (which is 1/3) for the first time.

My question is in past HSC or other papers must we be able to spot the integration coefficients by inspection? I for one know the integrated value of x^2 = is x^3/3 and when you substitute a value of x=1 or x=-1 you can determine the sign whether it be positive or negative.

How did you integrate the LHS, I tried substitution but it got ugly

 

[Drsoccerball]

Re: HSC 2015 3U Marathon

How did you integrate the LHS, I tried substitution but it got ugly

Let u = (1+x)^n

 

[davidgoes4wce]

Re: HSC 2015 3U Marathon



Not sure how to go about this .

 

[flavurr]

Re: HSC 2015 3U Marathon

Not sure how to go about this .

Is the answer possibly x/(x+1) ?

 

[davidgoes4wce]

Re: HSC 2015 3U Marathon

Is the answer possibly x/(x+1) ?

That is the answer. Any idea on how to explain it?

 

[davidgoes4wce]

Re: HSC 2015 3U Marathon

Going to listen to Omi-Hula Hoop to get more motivated for maths.

 

[flavurr]

Re: HSC 2015 3U Marathon

That is the answer. Any idea on how to explain it?

Sorry for how its set out and all. And I dont know if theres a proper ext way of doing it