C) y=-2x
1)Perpendicular lines have the slope equal to the reciprocal multiplied by -1 of the original line.
2) As the given line is y = 1/2x + 1 and the point that is intercepted by (1,-2) we can state the following
Original line:
Slope m = 1/2
Point
Perpendicular line
slope = -2
Let's plug into the slope-intercept formula the given point, to find b the linear coefficient
y=mx +b
-2=-2(1) +b
-2 =-2 +b
-2+2=b
b=0
So the function is, y=-2x
