Question

(ii) If two lines are perpendicular to each other having their slopes m1 and m2 then m1. m2 is equal to
(a) -1
(b) 1
(c) 0
(d) None of these​

Answer 1

Answer:

none of these is equal to m1

Answer 2

Given :

Two lines are perpendicular to each other having their slopes m1 and m2

To Find:

m1. m2

Step-by-step explanation:

• Let us take we have a line that is $y=m_{1}\times x +c_{1}$ where we have the slope of the line as $m_{1}$ and with intercept $c_{1}$.
• For the two lines to be perpendicular the product of their slopes should be  $-1$ .
• So the line equation perpendicular to the given line will be with slope $m_{2} =-1\div m_{1}$
• As the two lines are perpendicular so the angle between the lines become 90° and the other slope can be found by the formula

$tan(angle)=(m_{2}- m_{1})\div (1+ m_{1}m_{2})$

• Here angle is the angle between two lines whose slopes are given . And remember that the value is always taken as positive as there is modulus in the formula .

The final answer is -1