Straight line problem

[Superman]

A straight line L is perpendicular to y = 3x-1 and passes through (1,4). Find the equation of the line.

[Complex]

y = 3x-1 and passes through (1,4).

gradient of L = 3, gradient of perp. = -1/3

using y=mx+c sub y=4 and x=1 into the equation
4=3(1)+c
c=1
then the answer is y=-1/3x+1