WP 34S problem in solving f'(x)=0

[walter b]

(02-18-2015 02:53 PM)Dieter Wrote:  Then the manual should also reflect this. My 3.2 version says:

Quote:f’(x) will look for a user routine labeled 'δx', returning a fixed step size dx in X.

If both delta and X are case insensitive I think this is an important detail that has to be mentioned. Otherwise the user may code a program starting with label ΔX, being confident that it does not interfere with the derivative functions as they require "...a user routine labeled 'δx'". Typing an uppercase "ΔX" also is easier and faster. Walter: please update the manual in this regard.

Already done for v3.3 (since June 2014 at least). The IOP reads:

Quote:ATTENTION: f’(x) will look for a user routine labeled δx (or δX, Δx, or ΔX, in this order), returning a fixed step size dx in X. If that routine is not defined, dx = 0.1 is set for default (arbitrary, but it had to be specified).

(02-18-2015 02:53 PM)Dieter Wrote:  BTW what is the sequence the derivatives search for the delta-x label? δx → δX → Δx → ΔX?

Please see above.

d:-)