Solve equation with vectors as variables

Hello everybody,

I´m trying to solve an equation with only one unkown, where some of the other terms are vectors. The equation looks like this:

(rG_i+dnu_i*drG_pp)*(rG_i+dnu_i*drG_pp)'+(nu_i+dnu_i)*Fne*Fne'=0

where rG_i,drG_pp and Fne are column vector, nu_i is a scalar and dnu_i is the known (scalar too).

I have tried to solve it symbolically (solve function) but it treats first all the variables as scalars, so after substituing the result is not correct. I think the solution must be obtained numerically to resolve this issue. I tried with vpasolve but it doesn´t work either.

Does anyone have any idea how to solve this?

Thanks for your help in advance.

Carlos

[Ahmed A. Selman]

Can you specify how you used columns vector and a scalar in a symbolic op? Post your code, it might help people to help you. I also prefer to use simple representation of variables, e.g., what would be the problem if you put y instead of drG_pp, and x instead of dnu_i..etc?

Answer 1

[Roger Stafford]

If by the term “column vector” you mean a vector with one column, as is usual in matlab, then you have one unknown and as many equations to satisfy as the square of the length of these column vectors. In general there will be no solutions to systems like that. I believe you need to rethink either the problem or your description of it.

[Roger Stafford]

Hmm! I just noticed that this is a very old question. I wonder how it got here.