SOLUTION: how do i do through:(1,-2),perp.to y = - 1/2 x -5

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Question 828450: how do i do through:(1,-2),perp.to y = - 1/2 x -5
Answer by jim_thompson5910(35256) About Me  (Show Source):
You can put this solution on YOUR website!
y = - 1/2x -5 has a slope of -1/2

Flip the fraction: -1/2 ----> -2/1 = -2

Flip the sign: -2 ----> +2 = 2

So the perpendicular slope is m = 2

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y = mx + b

y = 2x + b ... plug in the perpendicular slope

-2 = 2(1) + b ... plug in the given point

-2 = 2 + b

-2 - 2 = b

-4 = b

b = -4

So we now know that m = 2 and b = -4. This means y+=+mx%2Bb turns into y+=+2x-4 which is the final answer