Maths Question: Coordinate Geometry?

Question

Find the equation of a line that is perpendicular to y = 3x - 1 and passes through the x-axis at 4

Working Out please, and step by step will be helpful =)

Answer 1

well in order to get a line perpendicular to y = 3x - 1 you have to find the a line with the negative reciprocal of 3, which is -1/3 so you get  y = -1/3x + 4.

http://www.regentsprep.org/rEGENTS/MATH/...  

Answer 2

Find the equation of a line that is perpendicular to y = 3x - 1 and passes through the x-axis at 4

Well, we have a point and the slope.  The slope is (-1/3) because the slope of the line perpendicular to it is 3 and the lines so opposite and reciprical slopes.  If it pass through the x-axis at 4 then we have the point (4,0)

(y-y1)=m(x-x1)

y=(-1/3)(x-4) or y=-x/3 + 4/3