How do you find the slope for y=18?

1 Answer
Sep 19, 2016

#0#

Explanation:

#y=18# allocates a constant value of 18 to y.

So no mater what value #x# is #y# will always be 18

The result is a straight line that is parallel to the x-axis and the line passes through the point on the y-axis #(x,y)->(0,18)#

'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Mathematically:

The slope is #("change in y")/("change in x")#

Let any point #P_1->(x_1,y_1)=(x_1,18)#

Let another point #P_2->(x_2,y_2)->(x_2,18)# where #P_1!=P_2#

Then slope #->m->("change in y")/("change in x") = (y_2-y_1)/(x_2-x_1) = (18-18)/(x_2-x_1) =0#