- #1
mistalopez
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Homework Statement
Write the slope intercept forms of the equation of the lines through the given point (a) parallel to the given line and (b) perpendicular to the given line.
Point: (2,1) Line: 4x-2y=3
Homework Equations
y-y1=m(x-x1)
y=mx+b
The Attempt at a Solution
I first put the line into slope intercept form: y=-2x+(3/2)
a) Next, I used point-slope to get the parallel line:
y-y1=m(x-x1)
y-1=-2(x-2)
y-1=-2x+4
y=-2x+5
*However, the correct answer should be y=2x-3
b) I used the reciprical of the slope to make it perpendicular: m = 1/2
Next I used the point-slope to find the perpendicular line of the equation.
y-y1=m(x-x1)
y-1=(1/2)(x-2)
y-1=(1/2x)-1 *Multiply both sides by 2 to remove fraction
2(y-1)=((1/2x)-1)2
2y-2=1x-2
2y=1x
y=1x/2
*However, the correct answer in the book is y=(-1/2x)+2
What am I doing wrong?