Answer:
Option D. Slope is 1 if the line is vertical
Step-by-step explanation:
we have
Part A) Slope is a measure of the steepness of the line
The statement is true
Because, the steepness of a line is measured by the absolute value of the slope.
Part B) Slope is the ratio of vertical change to horizontal change
The statement is true
Because the formula to calculate the slope between two points is equal to
so
Is the ratio of vertical change to horizontal change
Part C) Slope is zero if the line is horizontal
The statement is true
Because If the line is horizontal, the y-coordinate of two points is the same
therefore
The vertical change is equal to zero
Part D) Slope is 1 if the line is vertical
The statement is Not true
Because, if the line is vertical the slope is undefined