Question

the slope of line L is 1/3/ what is an equation of a line that is perpendicular to line L ?

A) y + 2 = 1/3x
B) -2+6=6y
c) 9x - 3y=27
D)3x=y=o

Answer 1

The slopes of perpendicular lines are negative reciprocals. You can get the negative reciprocal of a number by writing the number as a fraction, then flipping the fraction, then changing the sign. For example, the negative reciprocal of 2 is -(1/2). The negative reciprocal of 1/5 is -5

Answer 2

As mathstudent55 explained, a perpendicular to a given line will have a slope that is the opposite of the reciprocal of the original slope (assuming neither line is vertical or horizontal). In this case,\[m=\frac{1}{3} \implies m_{\perp}=-3\]So we are looking for a line with a slope of -3. Line A has a slope of 1/3 (parallel to the original line). Line B is a horizontal line (zero slope). Not sure what is going on with line D, but line C has a slope of -3. That's the answer.