Question 455145: find the slope of a line perpendicular to the line that passes through 3 9 and 7 15 Found 2 solutions by mananth, ikleyn:Answer by mananth(16949) (Show Source):
Plug value of the slope and point (3, 9) in
Y =mx+b
9.00=4.5+b
b=9-4.5
b=4.5
So the equation will be
Y =1.5x +4.5
PERPENDICULAR TO A LINE
Compare this equation with y=mx+b
slope m = 1.50
The slope of a line perpendicular to the above line will be the negative reciprocal
m1*m2=-1
The slope of the required line will be =-0.67
m= -0.67 ,point (3,9)
Find b by plugging the values of m & the point in
y=mx+b
9=-2.00+b
b=11
m=-0.67
The required equation is y=- 2/3x+11
m.ananth@hotmail.ca
You can put this solution on YOUR website! .
find the slope of a line perpendicular to the line that passes through (3,9) and (7,15)
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In the post by @mananth, there are many unnecessary calculations and many unnecessary words
and reasoning. His final answer -0.67 for the slope of a perpendicular line is incorrect.
I came to make a job in a way as it SHOULD be done.
The slope of the line passing through the given points is
m1 = = = = .
The slope of a perpendicular line is
= - = . ANSWER
Solved.
No more calculations are needed. No more words and no more reasoning are needed.
