## solve logarithmic inequalities with hp prime and khicas

HP-Prime CAS && Numworks N0110 & Casio Graph 90+e/35eii & TI-Nspire KhiCAS: Questions, documents, bugs, suggestions.
Federico Di Ceglie
Messages : 17
Inscription : sam. nov. 25, 2017 9:35 am

### solve logarithmic inequalities with hp prime and khicas

Goodmorning everyone,
Parisse, do you know why when I solve log2(3+x)+log2(3-x)>=1 hp prime otput x>=-sqrt(7) and x<=sqrt(7) and with Khicas output x>=-sqrt(-e^1+36)\2 and x<=sqrt(-e^1+36)\2?

parisse
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Inscription : mar. déc. 20, 2005 4:02 pm
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### Re: solve logarithmic inequalities with hp prime and khicas

Can you enter the precise commandline (algebraic syntax)?
There is no log2 function in giac.

Federico Di Ceglie
Messages : 17
Inscription : sam. nov. 25, 2017 9:35 am

### Re: solve logarithmic inequalities with hp prime and khicas

parisse a écrit :Can you enter the precise commandline (algebraic syntax)?
There is no log2 function in giac.
Both with prime and Khicas i use the template "log" of the two calculators, then I enter 2 as base of the logarithm.

parisse
Messages : 5044
Inscription : mar. déc. 20, 2005 4:02 pm
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### Re: solve logarithmic inequalities with hp prime and khicas

The log template of the nspire is not recognized, try log_2(3.0) then enter. Use natural logarithm or logb(x,b) instead.

Federico Di Ceglie
Messages : 17
Inscription : sam. nov. 25, 2017 9:35 am

### Re: solve logarithmic inequalities with hp prime and khicas

parisse a écrit :The log template of the nspire is not recognized, try log_2(3.0) then enter. Use natural logarithm or logb(x,b) instead.
With logb(x,b) Works, thank you very much