SOLUTION: Find the slope of the line containing the given points: (z + q,z) and (z - q,z) note: i know the formula of slope, m, is Y - Y1/X - X1. This is what i was thinking, please l

Algebra ->  Rational-functions -> SOLUTION: Find the slope of the line containing the given points: (z + q,z) and (z - q,z) note: i know the formula of slope, m, is Y - Y1/X - X1. This is what i was thinking, please l      Log On


   

Question 82377: Find the slope of the line containing the given points:
(z + q,z) and (z - q,z)
note: i know the formula of slope, m, is Y - Y1/X - X1. This is what i was thinking, please let me know where i'm going wrong. i have the solutions manual, but its not making sense. i don't know if x and x1 are both equal to z, or if you have to somehow factor z +/- q,z in both problems to get the solution. the manual has the first step typed out as: z-z/2-q-(z+q), and then of course 0/2q. however, i don't understand how the first step to the solution was solved. thank you. Joanna
Answer by 303795(602) About Me  (Show Source):
You can put this solution on YOUR website!
If the first point is labelled as (X,Y) and the second point is labelled as (X1,Y1)
Then for the first point X = z + q and Y = z
For the second point X1 = z - q and Y1 = z
m+=+%28Y+-+Y1%29%2F%28X+-+X1%29
Substitute the X, Y, X1 and Y1 values into the gradient equation.
m+=+%28z+-+z%29%2F%28%28z+%2B+q%29+-+%28z+-+q%29%29 Take (z - q) changes the signs to (-z + q)
m+=+%280%29%2F%28z+%2B+q+-+z+%2B+q%29
m+=+%280%29%2F%282q%29
ie the slope is zero. The line is parallel to the x axis.