Re: How to find answer to:

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#811

From: Robert Johnson
Date: Sat, 25 Mar 1995 14:08

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In article <3k4sll$49u@news.compulink.com>,
drizzt <drizzt@cml.com> wrote:
>A line passing through (6,2) and the positive arms of the x and y axises
>make a triangle with the area of 27units^2.  Through guessing, I have
>found the points on the y-axis to be (0,6) and the x-axis to be (9,0) but
>I can't figure out the formula to find it.  Please help.

Well, the general equation for a line passing through (6,2) is

    x-6
    --- = k
    y-2

To find the x-intercept, set y = 0 to get x = 6 - 2k.
To find the y-intercept, set x = 0 to get y = 2 - 6/k.
The area of the triangle is then (6-2k)(2-6/k)/2 which is

      2      2
    - - (k-3)
      k

Setting this equal to 27 and solving gives k = -6 and k = -3/2.
Thus, we get the two solutions { (18,0), (0,3) } and { (9,0), (0,6) }.

Rob Johnson
Apple Computer, Inc.
rjohnson@apple.com

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From: rjohnson@apple.com (Robert Johnson)
Newsgroups: can.schoolnet.math.sr,sci.math
Subject: Re: How to find answer to:
Date: 25 Mar 1995 06:08:01 -0800
Organization: Apple Computer, Inc., Cupertino, California
Lines: 29
Message-ID: <3l1841$5oa@apple.com>
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Summary: show how to find answer

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