Question

The lines shown below are perpendicular. If the green line has a slope of 2/5

, what is the slope of the red line?



A.


B.


C.
-

D.
-

Answer 1

C.
`-(5)/(2)}`

Explanation:

If two lines on a graph are perpendicular to each other, their slope is said to be negative reciprocals of each other. This means the slope of one, is the negative reciprocal of the other.

This can be represented as
`m_1 = (-1)/(m_2)`

Where,
`m_1, m_2` are slopes of 2 lines (i.e. the red and green lines given in the question) that are perpendicular to one another.

Thus, the slope of the red line would be:

`m_1 = (-1)/((2)/(5))`

`m_1 = -1*(5)/(2)}`

`m_1 = -(5)/(2)}`

The slope of the red line =
`-(5)/(2)}`