Newsgroups: php.internals Path: news.php.net Xref: news.php.net php.internals:70775 Return-Path: Mailing-List: contact internals-help@lists.php.net; run by ezmlm Delivered-To: mailing list internals@lists.php.net Received: (qmail 37264 invoked from network); 19 Dec 2013 23:09:34 -0000 Received: from unknown (HELO lists.php.net) (127.0.0.1) by localhost with SMTP; 19 Dec 2013 23:09:34 -0000 Authentication-Results: pb1.pair.com smtp.mail=swhitemanlistens-software@cypressintegrated.com; spf=pass; sender-id=pass Authentication-Results: pb1.pair.com header.from=swhitemanlistens-software@cypressintegrated.com; sender-id=pass Received-SPF: pass (pb1.pair.com: domain cypressintegrated.com designates 173.1.104.101 as permitted sender) X-PHP-List-Original-Sender: swhitemanlistens-software@cypressintegrated.com X-Host-Fingerprint: 173.1.104.101 rproxy2-b-iv.figureone.com Received: from [173.1.104.101] ([173.1.104.101:63146] helo=rproxy2-b-iv.figureone.com) by pb1.pair.com (ecelerity 2.1.1.9-wez r(12769M)) with ESMTP id AA/70-42949-DAC73B25 for ; Thu, 19 Dec 2013 18:09:34 -0500 Received: from [192.168.0.2] ([184.248.4.139]) by rproxy2-b-iv.figureone.com (Brand New Heavy v1.0) with ASMTP id EJC06105 for ; Thu, 19 Dec 2013 15:09:05 -0800 Date: Thu, 19 Dec 2013 18:08:45 -0500 Reply-To: Sanford Whiteman X-Priority: 3 (Normal) Message-ID: <1953165930.20131219180845@cypressintegrated.com> To: Andrea Faulds In-Reply-To: <52B37569.90205@ajf.me> References: <52B36BFC.4080708@lerdorf.com> <52B370F4.5010909@lsces.co.uk> <1077500642.20131219173431@cypressintegrated.com> <52B37569.90205@ajf.me> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Subject: Re: [PHP-DEV] Re: power operator (again) From: swhitemanlistens-software@cypressintegrated.com (Sanford Whiteman) > So I'm really confused now as to why people think -2 ** 2 should equal > 4. -2=B2 is -4. Why should -2**2 equal 4? Maybe the reason is lazy use of parentheses by math teachers? Imagine a teacher writing "-2 -1 0 1 2" on the board, then later adding the exponent: "Now, we take the square of each." The "-" and "2" might seem to be stuck together, since they were on the board first (?). And the main takeaway for students is that the square of a negative is positive, so the parens aren't emphasized at that particular time. Just an idea.... -- S.