Yes, it is true; slope zero is no slope.
A line with an undefined slope is a vertical line. A line with a slope of zero is a horizontal line. If you use the formula for slope m = (y2-y1) divided by (x2-x1)... For an undefined slope you will get zero in the denominator, which you cannot have because you cannot divide by zero. For a slope equal to zero, you will get a zero in the numerator. Zero divided by any non-zero denominator, will give you a slope of zero.
The slope when you get a zero on top would be zero. Zero divided by any number is zero.
positive slope negative slope undefined slope zero slope
Horizontal lines always have a slope of zero. (i.e completely flat, level surfaces have a slope of zero). However a line does not have to have a slope of zero in order to be a line.
A line with slope of zero is horizontal. A line with no slope is vertical because slope is undefined on a vertical line.
Flat slope is slope equals zero.
A horizontal line has a slope of zero. For a vertical line, the slope is not defined (change of y / change of x would result in a division by zero).A horizontal line has a slope of zero. For a vertical line, the slope is not defined (change of y / change of x would result in a division by zero).A horizontal line has a slope of zero. For a vertical line, the slope is not defined (change of y / change of x would result in a division by zero).A horizontal line has a slope of zero. For a vertical line, the slope is not defined (change of y / change of x would result in a division by zero).
A line with a slope of zero is a flat, vertical line.
run as in slope of a line is zero . horizontal lines have no slope and vertical lines have a slope of zero
positive slope negative slope zero slope undefined
The parallel line would also have a slope of zero (both are horizontal lines).