## 15 Reputation

5 years, 135 days

## How to compute normal (and inverse norma...

Maple

Hi, how can you compute the normal distribution value (in my case the standard normal distribution) of a value and likewise the inverse normal distribution for a given random number in Maple?

I haven't really found any way to do this easily like you can in e.g. Excel or Matlab.

For example if I have a value z = 2.7102, I can in Matlab find the standard normal distribution value as:

Φ(z) = cdf('normal',z,0,1) and inversely z = norminv(Φ(z) ,0,1)

Or in Excel: Φ(z) = normdist(z,0,1) and z = norminv(Φ(z) ,0,1)

How to do this in Maple?

## How to take derivative of a function wit...

Maple 2017

Hi, how can you in maple take the derivitve of a function that consists of sum terms in it? (preferable in document mode)

For example I have this expression (from a math book):

f = N+k*(sum(ln(x__i-B), i = 1 .. N))-N*k*(sum((x__i-B)^k*ln(x__i-B), i = 1 .. N))/(sum((x__i-B)^k, i = 1 .. N))

What I then want to do is to derive this function with respect to k.
However just writing the expression like above it seems like mable doesn't keep the summation terms but evaluates them in a sense. So not sure how to set it up correctly in order to make the derivitive.

Taking the derivitive of f with respect to k, the solution should give something like this:

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