100percent
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- Oct 28, 2004
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- HSC
- 2005
justchillin is a math dude, not word smith
When you think about it, it's quite an anomaly that in order to directly apply the 'reverse chain rule', you need to apply the 'chain rule' to the integrand. Hehe.justchillin said:Dont embarrase urself by correcting me... I was talking about the chain rule in the differentiation of the thing to be integrated...
I really hope, for your sake, that you DIDN'T do that.香港! said:^
i just wrote
int. cosxsin^2x dx=int. sin^2 x d(sinx)=sin³x\3+C
i hope that will give me full marks lol
DRAGONZ said:I really hope, for your sake, that you DIDN'T do that.
The integral had limits ... in which case, I hope that you just forgot that it had limits when you wrote your explanation two minutes ago.
And hey Daniel! How'd you go, mate? Adam says he didn't get over 80 ... what's the world coming to at our school?!? And Jonathan's hopes of 84 were dashed because he totally missed the induction question .. he didn't see it.
Oh well. There's still at least another 10 or 15 people who I can think of at school who could conceivably get 82, 83 or 84. I'm still so annoyed about the amount of time I spent on the one probability question. I would've had 82 otherwise, because I ran out of time
edit: here it isMarsBarz said:You know what's funny? Just one or two days before the extension examination, someone posted a thread in the maths forum with that same integral. Had I not read that thread at 3AM the day of the exam I would probably not have known how to do that question haha.
So thanks to whoever it was that posted it in the maths forum. You my friend, helped me gain some easy marks .
Well he's not doing 10 units ..Raginsheep said:Sif adam needs 3u. It proabaly won't even count for him unless he's doing 10 units...
suck my dick, 4u <> more work. You don't get better marks because you work harder, you get stereotypically better marks because your exposure to mathematics is considerably greater and thus your focus less shared amongst other subjects relative to a 3u student. The BOS doesn't go ohhh the 4u kids do more work, here lets chuck in a 4u question buddy... get over yourself.PiGMAN said:and I object to the anti-4unit sentiment in this forum. We do more work than you, thus our marks are better, period.
Of course not, because I know the substitution method. However, I just wanted to show that you can use a "3U only" method to solve this integral, that is all .buchanan said:icycloud, are you going to do all that just for 2 marks? I don't think so.
That is incorrect. The syllabus has different allowances for integration of trigonometric functions. I refer you to page 71 of the syllabus where, amazingly, an example of what integrals should be able to be completed by 3U students is the exact question in the exam is givenbuchanan said:jarro_2783's teacher is correct.
Page 66 of the 3 unit syllabus says "In all examples the substitution is to be given."
http://www.boardofstudies.nsw.edu.au/syllabus_hsc/pdf_doc/maths23u_syl.pdf