Which of the following lines are perpendicular to the line y=1/2x+4
A line is perpendicular to another line if and only if its slope is the negative reciprocal of the slope of the given line.
The given line has a slope of 1/2.
The negative reciprocal of 1/2 is -2/1 or -2.
Therefore, the lines that are perpendicular to y=1/2x+4 have a slope of -2.
The equations of the lines with a slope of -2 are:
y = -2x
y = -2x + 3
y = -2x - 5