## 191 Reputation

13 years, 193 days

## How to differentiate multiple times...

Maple
Hi, I have function like t^2+t+1 and I want to differentiate it with respect to time and set it an a new function, in order to calculate its derivation at some points. for example: a1_Func := (t)-> t^2 + t + 1; a2_func:=d/dt a1_Func(t); it works fine, but I can not call a2_func(t) at t=2 sec for example and it gives me an error saying "Error, (in a2_Func) invalid input: diff received 2, which is not valid for its 2nd argument". Please let me know how I can tell that the second function is also a function of time? Thank you,

## How I can simplify an expression based o...

Maple
Hi, I am working on a complicated expression. For the matter of simplicity, I want to define some new variables in order to express it in a more concise form. For example, where ever I have p^2/q^2, I want in to be replaced by a new defined variable like s, which is defined the same, i.e. p^2/q^2. So an expression like p^2/q^2 + 3 will turn to s+2. Please let me know if maple can do it, and if yes, how? Thanks, Hamidreza

## How to truncate a series of O(n)...

Maple
Hi everybody, I have a series and I want maple to truncate small variations of a variable of the order greater than n. For example, series1:=1+x+x^2+O(x^3) = 1+x+x^2. Thank you,

## dsolve does not give me neither the answ...

Maple
Hi everybody, I execute this code: But dsolve does not give me any response! Do you know what the problem could be? Thank you,