What is this problem and where did I find it?



I have been sharing some math problems with friends and one of them
went something like this:

You have a calculator with 0 in the display, and the only keys that
work are the sin, cos, tan, arcsin, arccos, and arctan keys. Prove
that you can obtain any rational number (?) assuming that the
calculations are done with absolute accuracy and that you can display
an arbitrary rational number.

I am not sure that this is the correct statement of the problem.
Please let me know the correct statement of the problem and, if you
know, where on the web I found it.


In return I offer you a problem that comes from Martin Gardner's column
in Scientific American from a long time ago:

Come up with a 10 digit number (base 10) with the property that the
left-most digit tells the number of 0's in the whole number, the next
digit over tells the number of 1's, ..., the last digit tells the
number of 9's in the whole number.

Note that if I posed the problem in base 4 rather than in base 10, an
answer would be 2020 since it has 2 0's, 0 1's, 2 2's, and 0 3's.

To make this problem considerably more interesting, find all solutions
to this problem for every base n. I will mention that for some value a
< 10, there is a unique solution for every base b > a.


If anyone is interested I will either drag out or recreate my solution.



Regards,
Achava

.



Relevant Pages

  • Re: home-built calculator
    ... > My son would like to build a calculator, basic four function, ... > for a science fair project for next year. ... most multi-digit 7-seg displays can only display ... displaying each digit in rapid succession. ...
    (sci.electronics.misc)
  • Re: Complacency
    ... Show them the resulting display of a long line of their favorite digit. ... :: were unable to get sensible answers, so they called in the manager. ... :: The manager went off and brought back a calculator. ... :: I was the only person in the shop and I think all this took at least ...
    (alt.support.diabetes)
  • Re: tech: Stern displays issues
    ... The easy one - The six-digit match/credit display is missing the ... 10'000's digit (which is the tens digit of the credits left half of the ... problem, and two, the 100K resistor in this circuit registers 97K ohms, ... 300K resistor in the other bad circuit would show 297 for a single beat, ...
    (rec.games.pinball)
  • Simple GUI application attempted.
    ... if the digit to be displayed is ... It would be nice if the ColorModel classes had 'set' methods, ... DigitDisplayImage class, after which the following code example would ... work to display the digit "4". ...
    (comp.lang.java.help)
  • Re: Number Of Decimal Digits In Frequency Display
    ... >> Is the signle digit in the decimal poriton of the frequency display, ... newsagents in the city used to stock the South/West and London ... he hasn't seem more than one place of decimals. ...
    (alt.radio.digital)

Loading