terminology: number minus it's reciprocal?

circlemaker · 2011-09-23 15:26:31

What's the official term for when you subtract a number with it's reciprocal? I can't seem to find anything on a google search, probably due to using the wrong keywords.

For example, if you take the square root of 3 (1.732) and subtract it's reciprocal from it (0.557), you end up with 1.154 (4/3 squared). I'm just wondering what this operation is called.

Btw I found this pattern by experimenting with it: 1/2, 4/3, 9/4, 16/5... etc. (*all squared).

bobbym · 2011-09-23 16:47:53

Hi circlemaker;

I am not understanding what you mean by 1.154 (4/3 squared)? Could you show your workings?

circlemaker · 2011-09-23 16:54:09

4/3 = 1.333
1.333 squared is 1.154

bobbym · 2011-09-23 17:11:33

Hi;
You mean the square root or root as it is sometimes called. Squared means multiply by itself.

You can derive your idea algebraically.

Squaring this we get:

So:

For n = 7 just plug into the bottom formula,

circlemaker · 2011-09-23 17:41:05

Oh, lol.... so I had the terminology backwards? Math.sqrt(n) is where I got that from (computer speak). Should the function be called Math.root(n) instead? :cool

Annnyway, is there a proper word or phrase to describe my original question? n-(1/n)

Thanks again!

bobbym · 2011-09-23 17:53:57

Usually I see sqrt for square root in computer languages, or something similar.

A phrase for that, I do not know of one.

circlemaker · 2011-09-23 18:13:47

Yeah lol I realized how that sounded after posting.

I had the two confused for a while. Squared, square root... squirt, sqrt, sqrd... they blend together. Thanks for clearing that up.

Umm, still nothing on my original question?

bobbym · 2011-09-23 18:18:21

Hi;

Sorry about that one, but I do not know what the name of n - 1 / n is called. It is hard to believe but not everything in math has a name.

Math Is Fun Forum

#1 2011-09-23 15:26:31

terminology: number minus it's reciprocal?

#2 2011-09-23 16:47:53

Re: terminology: number minus it's reciprocal?

#3 2011-09-23 16:54:09

Re: terminology: number minus it's reciprocal?

#4 2011-09-23 17:11:33

Re: terminology: number minus it's reciprocal?

#5 2011-09-23 17:41:05

Re: terminology: number minus it's reciprocal?

#6 2011-09-23 17:53:57

Re: terminology: number minus it's reciprocal?

#7 2011-09-23 18:13:47

Re: terminology: number minus it's reciprocal?

#8 2011-09-23 18:18:21

Re: terminology: number minus it's reciprocal?

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