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mun Member of the 'S.O.S. Math' Hall of Fame
Joined: 28 Dec 2007 Posts: 367
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Posted: Sat, 7 Nov 2009 18:09:46 UTC Post subject: two answers but i got only one |
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Find the direction in which a straight line must be drawn through the point (–1, 2)so that its point of intersection with the line be at a distance of 3 units from this point.
my work
i solved this and got the answer a line parallel to x axis .
first i find the equation of required line by taking its slope as m .i e [y-2=m(x+1)]. then i found the point of intersection of y-2=m(x+1) with the line x + y = 4 . after applying distance formula i got the answer as m=0 i.e a line parallel to x axis which is correct if we do calculation wise . but there is another answer which is a line parallel to y axis and i have checked this answer is geometrically correct.why analytically second answer is not coming.where is the fallacy. _________________ There is no god in this world except PARENTS and i have lost ONE |
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robbwrr Member of the 'S.O.S. Math' Hall of Fame
Joined: 10 Jan 2005 Posts: 3082 Location: baltimore, md
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Posted: Sat, 7 Nov 2009 20:39:15 UTC Post subject: |
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Let (t,4-t) be the point on line x+y=4 then
produces two solutions etc. _________________ "Those things that hurt, instruct."
-- Ben Franklin |
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mun Member of the 'S.O.S. Math' Hall of Fame
Joined: 28 Dec 2007 Posts: 367
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Posted: Sun, 8 Nov 2009 07:10:07 UTC Post subject: reply |
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| robbwrr wrote: | Let (t,4-t) be the point on line x+y=4 then
produces two solutions etc. |
Good morning sir
thanks sir
sir why the slope method fail here. _________________ There is no god in this world except PARENTS and i have lost ONE |
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Shadow Moderator

Joined: 30 Mar 2005 Posts: 4528 Location: Urbana, IL
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Posted: Sun, 8 Nov 2009 19:02:31 UTC Post subject: Re: reply |
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| mun wrote: | | robbwrr wrote: | Let (t,4-t) be the point on line x+y=4 then
produces two solutions etc. |
Good morning sir
thanks sir
sir why the slope method fail here. |
What is the slope method? _________________ (\ /)
(O.o)
(> <)
This is Bunny. Copy Bunny into your signature to help him on his way to world domination |
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outermeasure Member of the 'S.O.S. Math' Hall of Fame
Joined: 29 Dec 2008 Posts: 1498 Location: 127.0.0.1, ::1
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Posted: Mon, 9 Nov 2009 00:32:24 UTC Post subject: Re: reply |
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| mun wrote: | | robbwrr wrote: | Let (t,4-t) be the point on line x+y=4 then
produces two solutions etc. |
Good morning sir
thanks sir
sir why the slope method fail here. |
Because you assumed the slope is finite. (Indeed, you would have cancelled m^2 from both side....) _________________
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