I have an expression to define some coordinates in a region between $X_l$ and $X_u$, where $X_u > X_l$:

$$X_n = X_l + dx \sum_{n=0}^{N} (1-\delta _{n,0}) A^n $$

For $n = 0$ this gives $X_0 = X_l$. My aim is to find the number of terms, $N$, required for $X_N = X_u$ assuming all other terms in the expression are known.

The summation over the power series is where I'm struggling - remove the summation and this is simply rearrange and use a log to find n, but I'm not sure how to manipulate the expression with the summation present. I feel like this has a simple solution I'm overlooking, but any thoughts are appreciated.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Browse other questions tagged or ask your own question.