Math (PreCalculus)
posted by K.C on .
Find an equation of the line containing the points (8,6) and (8, 4)
so far i've tried yy1=m(x+x1) but currently cannot get the answer....TT
the answer is suppose to be x=8
plz show the work so i can study form it and do it myself the next time... thnx in advance

did you not notice that the slope is undefined?
(slope = (4 + 6)/(88) = 2/0)
so you have a vertical line.
All vertical lines are of the form x = ? , where the ? is simply the x coordinate of any point on the line
Thus x = 8
btw, a horizontal line would be of the form
y = ? , where ? is the y coordinate of any point on the line , (all the y's would be the same).
If you really insist on using your method, you could go ...
y  (6) = (2/0)(x  8)
then 0(y+6) = 2(x8)
0 = x8
x = 8
but that is rather silly 
slope = m = (Y2Y1)/(X2X1) = (48)/(88)
Oh my, we have a problem, the slope is undefined because of zero denominator.
The line with infinite slope goes straight up, constant x
so the solution is
x = 8