need help finding line through (1, 1), perp. to 3X+4Y=12

runlemmingsrun

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Sep 11, 2006
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Please help in solving:

A line that passes through (1,1) and is perpendicular to the line 3X+4Y=12.
 

wjm11

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Nov 13, 2004
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A line that passes through (1,1) and is perpendicular to the line 3X+4Y=12.
First figure out the slope in the given line. Next recognize that the slope of a line perpendicular to this will be the negative inverse of that slope. For example, if the first line had a slope of 2, a line perpendicular to it would have a slope of –1/2. Once you have calculated the slope, combine that information with the point you know, (1,1), to write the equation of your new line. The easiest way would be to put it in “point-slope” form.
 

wjm11

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Nov 13, 2004
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A line that passes through (1,1) and is perpendicular to the line 3X+4Y=12
Hello Runlemmingsrun,

Please keep your questions in the open forums -- no need for personal messages; that way everyone can help or learn from the questions and answers.

As I mentioned before, the first step is to find the slope of the given equation:

3X+4Y=12
First, subtract 3X from each side.
4Y = -3X + 12
Next, divide both sides by 4.
Y = -(3/4)x + 3

The slope of this line is -3/4.

Can you proceed from here? What have you tried so far?
 

wjm11

Senior Member
Joined
Nov 13, 2004
Messages
1,417
hi

I finally got the following equation upon solving:

4x-3y=1

is it correct?
Yes, this is correct.

Please show your work next time -- and use the forums rather than personal messages.
 
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