Comments on: DA Retrospectively: 18th October, 2004 http://datrippers.com/2010/02/01/da-retrospectively-18th-october-2004/ "A force for good", David Astle (DA) Tue, 07 Feb 2012 22:28:12 +0000 hourly 1 http://wordpress.org/?v=3.1.2 By: RobT http://datrippers.com/2010/02/01/da-retrospectively-18th-october-2004/#comment-15503 RobT Mon, 04 Apr 2011 20:47:12 +0000 http://datrippers.com/?p=656#comment-15503 I enjoyed this one and even remembered a couple of them (but only after I had got them out)!. Back to the future. I enjoyed this one and even remembered a couple of them (but only after I had got them out)!. Back to the future.

]]> By: AS http://datrippers.com/2010/02/01/da-retrospectively-18th-october-2004/#comment-3796 AS Thu, 04 Feb 2010 05:17:52 +0000 http://datrippers.com/?p=656#comment-3796 Although i² is no different to any other expression that equals -1 or 1, for instance 5 - 4 or 6^0, so calling i² a solution is cheating. Although i² is no different to any other expression that equals -1 or 1, for instance 5 – 4 or 6^0, so calling i² a solution is cheating.

]]> By: AS http://datrippers.com/2010/02/01/da-retrospectively-18th-october-2004/#comment-3795 AS Thu, 04 Feb 2010 05:11:49 +0000 http://datrippers.com/?p=656#comment-3795 The dots is ridiculously good. Very happy about discovering that one, if not solving it right out. The discussion about COT reminded me somewhat of the discussion about the 66% clue of a while ago now: a lot of nitpicking over something that was essentially not that big of a deal. But of course, this is what the site is about and what I have again and again demonstrated a fondness for. And I also had another thought: i² is also a possible solution to 2x = 1 / 0.5x. The dots is ridiculously good. Very happy about discovering that one, if not solving it right out.

The discussion about COT reminded me somewhat of the discussion about the 66% clue of a while ago now: a lot of nitpicking over something that was essentially not that big of a deal. But of course, this is what the site is about and what I have again and again demonstrated a fondness for.

And I also had another thought: i² is also a possible solution to 2x = 1 / 0.5x.

]]> By: AG http://datrippers.com/2010/02/01/da-retrospectively-18th-october-2004/#comment-3794 AG Thu, 04 Feb 2010 05:04:35 +0000 http://datrippers.com/?p=656#comment-3794 Modesty forbids detail, but I'll nominate myself as extremely well qualified in both maths and English to offer my opinion on the COT issue. AS is right in the most narrow and precise mathematician's sense, but only to that extent. f(x) is a function. But where f is a simple one-term relation like cotangent, to call that a function for short is commonplace. I like to nitpick definitions (see flag/exhaust this week), but to object to COT on that distinction is over the top IMO. If anyone asked me "Is cotangent a trigonometric function?", I'd say "Of course it is." Glad you finally saw the dots, AS. A beautifully disguised ripper, isn't it? I was halfway through compiling a complaint about it on Saturday when it suddenly dawned on me and graduated from confusion to clue of the week! As I posted at the time, brilliant and scrupulously fair. Modesty forbids detail, but I’ll nominate myself as extremely well qualified in both maths and English to offer my opinion on the COT issue. AS is right in the most narrow and precise mathematician’s sense, but only to that extent. f(x) is a function. But where f is a simple one-term relation like cotangent, to call that a function for short is commonplace. I like to nitpick definitions (see flag/exhaust this week), but to object to COT on that distinction is over the top IMO. If anyone asked me “Is cotangent a trigonometric function?”, I’d say “Of course it is.”

Glad you finally saw the dots, AS. A beautifully disguised ripper, isn’t it? I was halfway through compiling a complaint about it on Saturday when it suddenly dawned on me and graduated from confusion to clue of the week! As I posted at the time, brilliant and scrupulously fair.

]]> By: AS http://datrippers.com/2010/02/01/da-retrospectively-18th-october-2004/#comment-3785 AS Wed, 03 Feb 2010 05:33:46 +0000 http://datrippers.com/?p=656#comment-3785 Awesomeness! Fantastic! Awesomeness!

Fantastic!

]]> By: RB http://datrippers.com/2010/02/01/da-retrospectively-18th-october-2004/#comment-3784 RB Wed, 03 Feb 2010 05:29:15 +0000 http://datrippers.com/?p=656#comment-3784 OK, so you're drawing a distinction between "cotangent" and "cotangent x". And you've looked up "function" in the dictionary to support your argument. Trouble is that if you look up "cotangent" it will say it's a trigonometric function! Now for IDIOTS. Look at the clue; move along to the very end; what do you see there? OK, so you’re drawing a distinction between “cotangent” and “cotangent x”. And you’ve looked up “function” in the dictionary to support your argument. Trouble is that if you look up “cotangent” it will say it’s a trigonometric function!

Now for IDIOTS. Look at the clue; move along to the very end; what do you see there?

]]> By: AS http://datrippers.com/2010/02/01/da-retrospectively-18th-october-2004/#comment-3783 AS Wed, 03 Feb 2010 04:24:25 +0000 http://datrippers.com/?p=656#comment-3783 My definition of function, which coincides with ordinary dictionary definition: equation that can be plotted on a graph. My problem with COTANGENT: y = cot is nonsensical and cannot be plotted on a graph. y = cot (x) can be plotted, but not y = cot. My claim: COTANGENT alone can't be called a function, although COTANGENT (X), for instance, can. mic reckons my definition of function is not all that accurate in mathematical circles. I reckon he's right (I'm assuming mic means him). As for IDIOTS, I really need help. I've looked sideways, I've looked askance -- I've got nothing. My definition of function, which coincides with ordinary dictionary definition: equation that can be plotted on a graph.

My problem with COTANGENT: y = cot is nonsensical and cannot be plotted on a graph. y = cot (x) can be plotted, but not y = cot.

My claim: COTANGENT alone can’t be called a function, although COTANGENT (X), for instance, can.

mic reckons my definition of function is not all that accurate in mathematical circles. I reckon he’s right (I’m assuming mic means him).

As for IDIOTS, I really need help. I’ve looked sideways, I’ve looked askance — I’ve got nothing.

]]> By: RB http://datrippers.com/2010/02/01/da-retrospectively-18th-october-2004/#comment-3781 RB Wed, 03 Feb 2010 01:20:13 +0000 http://datrippers.com/?p=656#comment-3781 An extra word crept in there! Ignore the word "degree" in the line after the wikipedia link. An extra word crept in there! Ignore the word “degree” in the line after the wikipedia link.

]]> By: RB http://datrippers.com/2010/02/01/da-retrospectively-18th-october-2004/#comment-3780 RB Wed, 03 Feb 2010 01:16:39 +0000 http://datrippers.com/?p=656#comment-3780 I don't know where you're coming from on this, AS. It could be that you are making some really fine distinction here, but it's completely evading me! Both my dictionaries, and Google too, say cotangent is a function. See Wikipedia link: http://en.wikipedia.org/wiki/Trigonometric_functions#Reciprocal_functions And, when I did Maths at school and uni, degree, sine, cosine, tangent, and their reciprocals were all called "functions". OK, that was well over 40yrs ago and I may have changed a lot, but "cotangent" hasn't! BTW, your equation 2x = 1 / 0.5x does have another solution, namely x = -1 Now on to more interesting things: AS are you still puzzled by 4A? mic's hint to "think laterally" should be taken literally! i.e. look sideways! Can I hear the sound of you kicking yourself yet? I don’t know where you’re coming from on this, AS. It could be that you are making some really fine distinction here, but it’s completely evading me! Both my dictionaries, and Google too, say cotangent is a function. See Wikipedia link:
http://en.wikipedia.org/wiki/Trigonometric_functions#Reciprocal_functions
And, when I did Maths at school and uni, degree, sine, cosine, tangent, and their reciprocals were all called “functions”. OK, that was well over 40yrs ago and I may have changed a lot, but “cotangent” hasn’t!

BTW, your equation 2x = 1 / 0.5x does have another solution, namely x = -1

Now on to more interesting things: AS are you still puzzled by 4A? mic’s hint to “think laterally” should be taken literally! i.e. look sideways! Can I hear the sound of you kicking yourself yet?

]]> By: mic http://datrippers.com/2010/02/01/da-retrospectively-18th-october-2004/#comment-3779 mic Wed, 03 Feb 2010 01:08:52 +0000 http://datrippers.com/?p=656#comment-3779 Well, it means x = 1 or -1 While you seem to have a good grasp of doing mathematics, I think you are slightly mistaken about the terminology. The dictionary definition is slightly misleading because it tries to avoid the necessary supporting mathematical jargon http://en.wikipedia.org/wiki/Trigonometric_functions Well, it means x = 1 or -1
While you seem to have a good grasp of doing mathematics, I think you are slightly mistaken about the terminology. The dictionary definition is slightly misleading because it tries to avoid the necessary supporting mathematical jargon

http://en.wikipedia.org/wiki/Trigonometric_functions

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