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Question 253134: can somebody please help me?
i dont really understand this problem..
it says: write an equation that goes through the point (-3,5) and is perpendicular to y=3x + 2
can somebody please help?
please and thank you!
Found 3 solutions by hokies, Alan3354, richwmiller:
Answer by hokies(65)   (Show Source):
You can put this solution on YOUR website! The slope of the line that it is perpendicular to is 3 (y = mx + b, where m is the slope). The slope of the line is therefore -1 / (slope first line) = -1/3. This is the definition of the slope of a perpendicular line, -1 / (slope of the other line). So we have y = -x/3 + b so far. Now plug in the point (-3,5) and solve for b: 5 = 3/3 + b. b=4. Therefore, the equation for this line is: y = -x/3 + 4.
Answer by Alan3354(69443)  (Show Source):
You can put this solution on YOUR website! write an equation that goes through the point (-3,5) and is perpendicular to y=3x + 2
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The slope of y = 3x + 2 is 3.
The slope of lines perpendicular to it is the negative inverse, -1/3.
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Use y = mx + b and the point to find b:
5 = (-1/3)*(-3) + b
b = 4
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--> y = (-1/3)x + 4
Answer by richwmiller(17219)  (Show Source):
You can put this solution on YOUR website! Cut the bull. Everyone who submits a problem wants help and doesn't understand the problem.
Your situation and problem are not unique.
Actually it is quite basic.
You should be asking yourself why you don't understand. Where were you when it was explained? Where is the book that explains it? Where are your notes?
We are here to teach and you to learn not for us to do your homework.
Write an equation with slope and point is very common.
You have to do several things.
First, find the slope of the linear equation you were given
Ask yourself what the slope would be of a line perpendicular to this one
Lines which are perpendicular have slope whose product is -1
so if one slope is 1/2 the other slope will be -2
1/2*-2=-1
so the other slop=e will be its negative(minus) reciprocal fraction turned over.2/1 turned over becomes 1/2
1/2 turned over becomes 2/1
Where m is the slope and b is the y intercept when x=0
We are lucky that the given equation is in the right format.
y=3x+2
The slope is 3 and we want the negative reciprocal -1/3
so our equation is starting
y=-x/3+b
Now we need to find b
so we plug in the point we were given
-3,5
where x=-3 and y=5
y=-x/3+b
5=-(-3)/3+b
5=3/3+b
5=1+b
4=b
now we put it altogether and here is our equation
y=-x/3+4
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