Question

Lines a and b are perpendicular. The slope of line a is −2. What is the slope of line b?

Answer 1

1/2

Explanation:

if the one line's slope is m = –2, then the perpendicular line's slope will be m= 1/2 (the slope of a perpendicular line is the reciprocal of the slope of the first line)

Answer 2

`(1)/(2)`

Explanation:

I will call
`m_(a)` the slope of line
`a`, and
`m_(b)` the slope of line
`b`.

For two lines to be perpendicular, the following must be satisfied:

`m_(a)*m_(b)=-1`

in this case we know:

`m_(a)=-2`

so:

`(-2)*m_(b)=-1`

And clearing for the slope of line
`b`:

`m_(b)=(-1)/(-2) \\m_(b)=(1)/(2)`

The slope of the line
`b` which is perpendicular to line
`a` is
`(1)/(2)`