i have to define "n" functions variable with the index "i"

[lcoppelli]

i have to define "n" functions variable with the index "i" that goes from 1 to n, in the same way usually is defined a n components vector. The problem here is that the  components are not numbers but functions y=f(x). Than i have to do the summation  of these functions as you can see from the file attached. How can i define these functions? i have tryied but mathcad doesn't recognise it.

[Werner_E · Accepted solution]

I would suggest to create a function Mx(,x,i) instead.

In your sheet there are a lot of undefined variables and also the undefined function Mxf

Its not clear to me which expression are summed up in your sums.

It looks hat X[i and the second Mx(x)[i are NOT inside the sum which sums up for i.

Your function Mx has no return value for x=0 and x=a (also not for x outside of [0;A]) - it should have a return value for any input. Set it to 0 or to NaN in those cases.

[lcoppelli]

thanks! now the functions Mx are defined. i just attached a part of the entire file.this is why a lot of functions and variables are not defined.  the Xi and the second Xi has to be inside the sum which sums up for i. If i want to solve the equations that i wrote and find the Xi, how can i do? maybe i can define a vector X made of n components and in the equation i have to write the"i-th" component. Is it correct?

[Werner_E]

> how can i do?

Maybe like in the attached filed.

I am not sure what you are trying to do.

You have just 1 equation but 101 variables to solve for!

Mathcad will adjust one of them so that this equation is fulfilled, Sure not what you intend, I guess.

In the attached sheet I have changed n:=100 to n:=10 because I am quite impatient 😉

[lcoppelli]

Thank you very much! but something doesn't work. Maybe i haven't explained well what i want to do. i have attached the entire file. Read just what i have written in english. i hope to have been more clear now!