Question 152667
What is the equation of the line that passes through (4, -2) and is perpendicular to y = 1? @ The line that is perpendicular to y = 1 must be vertical, so it has undefined slope. Hence, it can only be the x coordinate of the defined point: x = 4. 
a. y = ½x + 4
b. y = -2
c. Insufficient
d. none of the above
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y = 1 is a vertical line, parallel to the y axis, so a line perpendicular to it will be parallel to the y axis.

Since is passes thru (4,-2), y has to equal -2.  So it's b, y = -2