The two lines (l x+my=n) and (l'x+m'y=n') are perpendicular... | Mathematics | SolveeIt | Solveeit

Today, August 18

Question

The two lines $l x+my=n$ and $l'x+m'y=n'$ are perpendicular if

A

ll'+mm'=0

B

lm'+ml'

C

lm+l'm'=0

D

lm'+ml'=0

Answer

ll'+mm'=0

Explanation

Solution

Product of slopes $= -1$
$? ll'' + mm' = 0$