Question

What is the equation of the line that goes through `(3,3)` and is perpendicular to `y=1/3x`?

Answer 1

`l_2=y=6-3x`

Explanation:

If `l_1` and `l_2` are orthogonal, then `m_(l_1)m_(l_2)=-1` and `m_(l_2)=-1/(m_(l_1))`

`m_(l_2)=-1/(1/3)=-3`

`l_2=y-3=-3(x-3)`

`y-3=-3x+3`

`y=6-3x`