Re: Decimal point before an operation Message #4 Posted by Chris Randle (UK) on 29 Jan 2011, 5:33 p.m., in response to message #3 by Jim Yohe
It's a great feature of the calculator, and wellimplemented, IMO. In case you're not familiar with HP triglyphs, "\v/" represents the square root symbol, "\>" a rightarrow, and "\pi" the symbol for pi.
In exact mode,
\v/4 > 2
because there's an exact decimal representation of the square root of four. But, because the square roots of two and 20 are irrational,
\v/2 > \v/2
\v/20 > 2*\v/5
Keeping the square roots there in case a later squaring operation is used. If you knew in advance that you wanted an approximate decimal fraction for the square root of two, you could type:
\v/2. > 1.41421356237
to convert back,
\>Q\pi(ANS(1)) > \v/2
\>Q\pi is available from the catalog menu (CAT)
The example on page 114 and the examples I've used assume the calculator is in algebraic mode. I prefer RPN mode, and Tim Wessman has produced an additional guide: "HP 50g Graphic Calculator Quick Start Guide" with all examples in RPN mode. If you haven't seen it, you can download a copy here:
HP 50g Graphing Calculator Quick Start Guide
Also, if you haven't seen a copy of the Advanced User's Reference Manual, which is definitely worth a look, you can get yourself a copy from here:
HP 50g/49g+/48gII graphing calculator advanced user's reference manual
