ATAR Notes: Forum
Archived Discussion => 2010 => End-of-year exams => Exam Discussion => Victoria => Mathematical Methods CAS => Topic started by: qshyrn on November 08, 2010, 06:32:04 pm
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MC Q20 from memory:
int(f(x),x,0,a)=a F(a)-F(0)=a
2*int(f(x/5)+3,x,0,5a)=??
my working out:
= 2 int(f(x/5),x,0,5a) + 6*int(1,x,0,5a)
= 2 (F(a)-F(0)) +30a
= 2a+30a
=32a
but this wasnt one of the options....
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40a is what I got. First one is 10a?
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I got 32 too. So i just thought stuff it and put the one that had 40.
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I used the substitution method as in spesh (which meant that the first integral was multiplied by 5). And I got 40a too.
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i just put 40
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I hope you're all right. Guesses FTW
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it had to be larger than 30a so it was either D or E.
Fortunately, I guessed the right one.
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I got 32a at first but then somehow got 40a.
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i just put 40
rofl, me too. had to be above thirty, and that first term was looking really 10ish to me.
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i did that ini mini maini mo thing on that question and it turned out right :)
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I used the substitution method as in spesh (which meant that the first integral was multiplied by 5). And I got 40a too.
You dont need spesh to do it? Haha
Once you separate the integrals it works out to be 10a + 30a because int(f(x/5),x,0,5a) =2*5F(a) = 10a, etc
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i just put 40
rofl, me too. had to be above thirty, and that first term was looking really 10ish to me.
yeah same i just calculated the other one, and was like, yeah about five times something equals 10, probs not 20 thats too big. so probably a 10+20
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Yeah I got 32 and put 40.
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I hope you're all right. Guesses FTW
+1
HI FIVE!!
Also half guessed the last one and got it right.
:D
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another case of vcaa fail.
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Can't even remember LOL probs just guessed. But i remeber i got 30something as well first.