Find the equation of the line which is parallel to the y axis and midway between the lines x=-1 ,x=3?

Since the line is parallel to the y-axis, its equation will be of the form x = k, where k is a constant.

Since the line is midway between x = -1 and x = 3, the x-coordinate of the line will be the average of -1 and 3, which is (3 - 1) / 2 = 1.

Therefore, the equation of the line which is parallel to the y-axis and midway between the lines x = -1 and x = 3 is x = 1.

The equation of a line parallel to the y-axis is x=k, where k is a constant.

The midpoint of the lines x=-1 and x=3 is (2,0).

Since the line is midway between the lines x=-1 and x=3, its x-coordinate must be the average of the x-coordinates of the two lines, which is (2,0).

Therefore, the equation of the line is x=2.