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Write an equation of the line perpendicular to the given line that contains P.

​P(4, -3); y=1/2x+3. Write an equation for the line in​ point-slope form.

User Fatmajk
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1 Answer

1 vote

Greetings!

Answer:

y = 2x - 5

Explanation:

First, we must find the slope of the current equation.

This is the number in front of the x.

Seeing as this is 1/2x, the slope of this line is 1/2

When finding the slope of a line perpendicular, you need to find the
(-1)/(slope)

So, in this case it is:


(-1)/((1)/(2) )

This gives the result -2, so the gradient on the perpendicular line is -2

Now, to find the equation of a line, you need to use:

y - y1 = m(x - x1)

Where y1 and x1 are the values in the coordinates (4 , -3)

So y1 = -3, x1 = 4, and m is a half. Plug these values in:

y - 3 =2(x - 4)

Expand the brackets by multiplying the contents by two:

x * 2 = 2x

-4 * 2 = -8

2x - 8

y - 3 = 2x -8

And now simply move the -3 over to the other side, making it a positive:

y = 2x - 8 + 3

Simplify:

y = 2x - 5

So the equation of the line is y = 2x - 5


Hope this helps!

User Brandog
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6.6k points