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July 05, 2020, 02:09:40 am

Author Topic: QCE Maths Methods Questions Thread  (Read 2818 times)

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A.Rose

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Re: QCE Maths Methods Questions Thread
« Reply #15 on: April 27, 2020, 05:56:57 pm »
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Hi!
I'm stuck on a question about Bernoulli sequences and the binomial distribution from Unit 4 Topic 3 Methods.
If it says 'at least' does this mean P(X>9)? And could you calculate that by doing P(X>9)=1-P(0≤X≤9)? I tried that and I didn't achieve the answer in the textbook.
Thank you!

Bri MT

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Re: QCE Maths Methods Questions Thread
« Reply #16 on: April 27, 2020, 08:35:51 pm »
+2
Hi!
I'm stuck on a question about Bernoulli sequences and the binomial distribution from Unit 4 Topic 3 Methods.
If it says 'at least' does this mean P(X>9)? And could you calculate that by doing P(X>9)=1-P(0≤X≤9)? I tried that and I didn't achieve the answer in the textbook.
Thank you!

Hi!

Your thinking is good here except that "at least" means greater than or equal to - not just greater than :)

So in your subtraction you shouldn't include the case where x=9

RuiAce

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Re: QCE Maths Methods Questions Thread
« Reply #17 on: May 27, 2020, 06:20:44 pm »
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Hi!
I have a question I'm stuck on from Unit 4 Topic 2 Methods. It's either really simple and I'm missing something or its generally a bit tricky. First time I read the question I thought of a right triangle but you can't assume that can you? Plus this Unit 4 methods, not Unit 1.  ;D
So if you can't assume it is a right triangle then how do you find the height? It reminded me of the ambiguous case but I'm not sure how/if to use that property to answer the question. I would greatly appreciate the help as I am doing a revision of Unit 4 Topic 1&2 in class this week.
Thank you!

At first glance, I actually think that it is really simple. Technically speaking, "the distance from the foot of the cliff to a boat", and "the height of the cliff above sea level", are exactly the ingredients of a right-angled triangle formulation!

I am surprised that this is considered a Unit 4 question instead of Unit 1. For all I know I could be missing something too, but my logic came from the wording of the question entirely.

Perhaps there's follow-up questions to this problem that are more Unit 4 based? Or perhaps there's an answer to aim for?