Slope of a Vertical line

Slope of a Vertical line A vertical line is the line that is parallel to the y axis as, the y-axis is the vertical line. The equation of the y axis is x = 0. Slope of a line is defined as raise over run. The slope of a straight line is calculated by the change in the y co-ordinates divided by the change in the x co-ordinates of any two points on the straight line. Example 1: Find the equation of the straight line parallel to y axis and passing through the point (3, 4)? Solution: Given, the line is parallel to the y axis. The equation of the y axis is x = 0. The lines are parallel so they have the same slope. The slope of the y-axis is undefined. Hence the slope of the vertical line is undefined. General form of the vertical line passing through (a, b) is x =a The line is passing through (3, 4). Therefore the equation of the vertical line is x = 3. Example 2: Find the equation of the straight line parallel to y axis and passing through the point (1, -5)? Solution: Given, the line is parallel to the y axis. The equation of the y axis is x = 0. The slope of the y-axis is undefined. Hence the slope of the vertical line is undefined. General form of the vertical line passing through (a, b) is x =a The line is passing through (1, -5). Therefore the equation of the vertical line is x = 1.