Just ask your calculator

[pier4r]

Found on a book preparing for nationwide tests after high school.

[KeithB]

Is that CAS or Home mode?

Home gives an error.

CAS gives infinity on the Prime.

For my HP71 it depends on the flag settings. If you work hard you can get NaN.

[pier4r]

The quote was from a McGraw Hill publication. Not related to any calculator manual.

[KeithB]

Sorry, forgot the 8^)

[Joe Horn]

(04-12-2017 05:13 PM)KeithB Wrote:  For my HP71 it depends on the flag settings. If you work hard you can get NaN.

On an HP-71B, after TRAP(IVL,2), 0/0 yields NaN, but 4/0 yields Inf. How do you get 4/0 to yield NaN?

[KeithB]

Have a bad memory? I thought every /0 yielded NaN.

[grsbanks]

Nope. Only 0/0 is undetermined mathematically.

x/0 for real value x!=0 is always +INF or -INF depending on the sign of x.

[SlideRule]

(04-18-2017 08:06 AM)grsbanks Wrote:  Only 0/0 is undetermined mathematically. x/0 for real value x!=0 is always +INF or -INF depending on the sign of x.

Could you cite your source, such as at Math-only-Math under Properties of Division, Property 4 is the following Note: In order to divide 6 by 0, we must find a whole number which when multiplied by 0 gives us 6. Clearly, no such number can be obtained. We, therefore, say that division by 0 is not defined.

BEST!
SlideRule

[pier4r]

(04-18-2017 08:06 AM)grsbanks Wrote:  Nope. Only 0/0 is undetermined mathematically.

x/0 for real value x!=0 is always +INF or -INF depending on the sign of x.

For the little that I know, this should be valid only with limits. I mean : the divisor (epsilon) approaching to zero in the formula x/epsilon