HSC 2012-14 MX2 Integration Marathon (archive) (2 Viewers)

[asianese]

Re: MX2 Integration Marathon

Need help with integrating this:
\frac\sqrt{1+x}\sqrt{3+x}

For those 99% of the time it's a rationalise the numerator problem.

 

[braintic]

Re: MX2 Integration Marathon

For those 99% of the time it's a rationalise the denominator problem.

Don't you mean rationalize the NUMERATOR?

 

[asianese]

Re: MX2 Integration Marathon

Don't you mean rationalize the NUMERATOR?

Yes I had this going through my head and doubled checked it. Sometimes Yr8 permeates the mind.

 

[dunjaaa]

Re: MX2 Integration Marathon

first one done , working on the the next 2 atm

 

[seanieg89]

Re: MX2 Integration Marathon

For those 99% of the time it's a rationalise the numerator problem.

What exactly do you mean by rationalise the numerator here?

 

[asianese]

Re: MX2 Integration Marathon

and you should be able to go from there.

 

[seanieg89]

Re: MX2 Integration Marathon

and you should be able to go from there.

Cool, that's what I thought.

 

[dunjaaa]

Re: MX2 Integration Marathon

Question 2 (i) and Question 3 (not sure if they're correct). I'll work out Q2(ii) tomorrow, need to go sleep, brain hurts Where do you get your questions from...

 

[asianese]

Re: MX2 Integration Marathon

Question 2 (i)View attachment 29866 and Question 3 View attachment 29865(not sure if they're correct). I'll work out Q2(ii) tomorrow, need to go sleep, brain hurts Where do you get your questions from...

Make them up, famous integration problems

 

[rumbleroar]

Re: MX2 Integration Marathon

and you should be able to go from there.

Thanks so much, I finally got it.

Is the eventual integral:
1/2 (rt((x+2)^2-1)) - ln (x+2 + rt((x+2)^2 - 1)

(only asking because there's multiple choice answers and they don't have the 1/2 for (rt((x+2)^2-1)))

 

[dunjaaa]

Re: MX2 Integration Marathon

this is what I got but that's one handy trick

 

[anomalousdecay]

Re: MX2 Integration Marathon

Where do you get your questions from...

By the time you finish HSC, you will be able to make your own questions easily.

I wasn't as great at 4U as the above people but integration problems are the easiest to make up on the spot. Even I can make them, so surely everyone else can.


And I think RR's one is from an ext.2 HSC paper (I remember doing that question).

 

[Kurosaki]

Re: MX2 Integration Marathon

View attachment 29867 this is what I got but that's one handy trick

I'm not sure (holiday mode still) but aren't you supposed to enclose the integrated function with brackets?

 

[dunjaaa]

Re: MX2 Integration Marathon

does it really matter lol

 

[anomalousdecay]

Re: MX2 Integration Marathon

Thanks so much, I finally got it.

Is the eventual integral:
1/2 (rt((x+2)^2-1)) - ln (x+2 + rt((x+2)^2 - 1)

(only asking because there's multiple choice answers and they don't have the 1/2 for (rt((x+2)^2-1)))

There is no 1/2 in front of that expression.

The derivative yields twice what is needed, yet when dividing by the new power, you get 0.5/0.5 which is just one.

 

[anomalousdecay]

Re: MX2 Integration Marathon

does it really matter lol

You can get away with it.

But in ext.2, use absolute value brackets just in case, so the marker knows that you know what you are doing.

 

[rumbleroar]

Re: MX2 Integration Marathon

There is no 1/2 in front of that expression.

The derivative yields twice what is needed, yet when dividing by the new power, you get 0.5/0.5 which is just one.

Haha yes nvm got it! Took me a bit of mental squinting to get there haha I think I stuffed up during the derivative

 

[rumbleroar]

Re: MX2 Integration Marathon

I'm not sure (holiday mode still) but aren't you supposed to enclose the integrated function with brackets?

Yes, this is what my teacher says and gets very pissed when we don't do it. Better safe than sorry.

 

[anomalousdecay]

Re: MX2 Integration Marathon

Yes, this is what my teacher says and gets very pissed when we don't do it. Better safe than sorry.

It just shows the marker that you understand all aspects of Maths, and can get them to think of you as a genuine e4 student.

 

[Sy123]

Re: MX2 Integration Marathon

A harder integral