Bug: HP Prime can't do Log's

[jebem]

(12-14-2015 07:52 AM)retoa Wrote:  

(12-14-2015 07:02 AM)Dieter Wrote:  Please forgive my ignorance, and maybe I get something wrong here, but: if there is a built-in function log(a, b) I would expect it to be evaluated with the usual 15 digit internal precision. Else there is no benefit compared to a manually calculated ln(a)/ln/b). ;-)

logb(81,3) returns the "right" answer 4 on my Prime, in both Home and CAS.

Are you getting a different result?

My physical PRIME gives different results depending on:
- What command we use: logb() or LOG()
- What environment we use: CAS or HOME

A) For logb(), it doesn't matter whether you are in HOME or in CAS mode:
logb(81,3) = 4
Ans-4 = 0

B) For LOG(), it depends on the environment:

B.1) HOME mode
LOG(81,3) = 3.99999999999
Ans-4 = -0.00000000001

B.2) CAS mode
LOG(81,3) = 4
Ans-4 = 0