John_Dirichlet

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5 years, 42 days

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These are questions asked by John_Dirichlet

Hi there,

            I am new to maple. I want to ask a simple question.

            If I have a array, and I want its each component to take natural logarithm. How can I do?

            Eg:[2 3 4]->[ln(2) ln(3) ln(4)]

            Thanks in advance.

Dirichlet

Hi guys.

           if an expression complicated as the following,  

sqrt(sqrt(9)*sqrt((1+(b+1)^2*c^2+((10/3)*b-2)*c)*(1+(b+1)^2*c^2+(2*b-2)*c))+3+(3*b^2+6*b+3)*c^2+(8*b-6)*c) , where b>0 c>0

is it possible to tell whether it could be positive? 

I used coulditbe command, however, it returned 'FAIL'.

Hi there,

            Recently, I encountered a problem. I have a function( omega as its variable)  (18)

 gamma*sqrt(4)*sqrt(omega^2*C2^2*R4^2/(C2^4*R4^4*beta^2*gamma^2*omega^4+C2^2*(1+gamma^2*(beta+1)^2-2*gamma)*R4^2*omega^2+1))

I tried to find a point where its first derivative equals 0. In this case, Maple returned four solutions. In my

question, both beta, gamma, R4 and C2 >0, I want it to return a real positive solution, the first term

in (19) (i.e. 1/(sqrt(beta *gamma) *1/R4 C2).

 

I know it is easy to find out the positive real roots in this case. This question seems to make no sense.

However, sometime I came across an expression complicated enough that I cannot tell whether it is real

positive.

Is there a approach to find a real positive solution of an symbolic eqution?

Thanks in advance!

 

                                                                     A University student in BeiHang University, Beijing

Hi,

   If I have a fraction like this w^2/(w^4+2*w^2+1) , how can I make it presented in Maple as  '1/(w^2+1/w^2+2)' (Both numerator and denominator divided by w^2) ?

Thanks in advance!

Hi,

     I now have a problem.

     I want to calculate first derivative of a function and make it a function with respect to a variable.

     For example,

     f:=x->x^2

     derivative:=x->diff(f,x)

 

     I expect derivative is a function, (i.e.  derivative(x)=2x) , So if I put 'derivative(2)',I should get 4 as results. However I get "Error, (in H_Mag_Derivative_2) invalid input: diff received 2, which is not valid for its 2nd argument".

     Could someone give me a hand? Very much appreciated.

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