News for hackers. Stuff that matters.

A comment on Ask HN: What is -2^2?. Parent comment

Re:Ask HN: What is -2^2? by yaks_hairbrush on Friday April 01, 2011 @11:21PM (#2399016)
HP48 is RPN, which sidesteps precedence issues. So, here you explicitly need to decide if you want 2 NEG 2 ^ (i.e. (-2)^2) or 2 2 ^ NEG (i.e. -(2^2)).

The traditional order of operations is what the TI series does. In essence, it assumes you want the second form.

By the way, on my HP50G in algebraic mode, typing '-2^2' does give -4.

[ Parent | on HN ]
Re:Ask HN: What is -2^2? by laujen on Saturday April 02, 2011 @11:14AM (#2400061)
I apologize. You are correct, the HP48gx is RPN only. Don't know why I thought otherwise. I had it in my head for some reason that 48 did both (it kind of does but not really) and that it gave the answer as 4.
[ Parent | on HN ]