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Need help, URGENT maths question: (4 Viewers)

1008

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I think you forgot to use product rules or quotient rules etc. where needed. Like for the (∂/∂r)[∂ƒ/∂θ* (sin(θ)/r)] term in that second line, you should use product rule because the second function here (sin(θ)/r) is dependent on r (the sin(θ) part is a constant wrt r, but the r isn't of course, so we do need to use product rule).
Right thanks I'll get back to you on that question. Any thoughts on the other one?
 

1008

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Had a few more questions regarding probability, if someone can help me (please):

For the first one: very that this function f is a probability density, that is, that:
f(x) is greater than or equal to zero and




Thanks
 

leehuan

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Pretty sure I asked Q61 already.

For the Laplace distribution just rewrite the integral as



Pretty obvious as to why f(x)>0
 

InteGrand

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Had a few more questions regarding probability, if someone can help me (please):

For the first one: very that this function f is a probability density, that is, that:
f(x) is greater than or equal to zero and




Thanks






 

leehuan

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Oh right that's how to do it... I was like how do I integrate this because I left my answers at home but I forgot about completing the square entirely


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1008

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Pretty sure I asked Q61 already.

For the Laplace distribution just rewrite the integral as



Pretty obvious as to why f(x)>0
Could you direct me to which thread you asked Q61 on?
 

InteGrand

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Thanks :)

Since I have exams coming up in a week :confused2: please excuse pile of questions I am hurling towards you IG :p

QUESTION (i)

(I said 'test' a lot below, I'm referring to the method for detecting illegal trades by that.)

















So for these Q's, the important things are to set out some notation at the start, write out the given data carefully in terms of our notation, figure out exactly what the Q's are asking in terms of our notation, and keep in mind the Law of Total Probability and Bayes' rule (as well as Pr(Ac| B) = 1 – Pr(A | B) and our other probability rules of course).
 
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InteGrand

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Wow thanks!

Here are some more, I have no idea what to do:
For the first one, partially differentiate the homogeneity equation wrt t (that's how you get n to pop out) and then sub. in t = 1 after that. To differentiate the LHS of that wrt t,

 
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leehuan

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That same question involving f(tx,ty) appeared in a past paper in a different form.



And I don't get the answers.





Sure ok... No idea why they changed the order of the variables of g but still ok...





What. How?
 

InteGrand

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That same question involving f(tx,ty) appeared in a past paper in a different form.



And I don't get the answers.





Sure ok... No idea why they changed the order of the variables of g but still ok...





What. How?
 
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1008

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That same question involving f(tx,ty) appeared in a past paper in a different form.



And I don't get the answers.





Sure ok... No idea why they changed the order of the variables of g but still ok...





What. How?
Wtf?
 

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