Question 1: Calculate the gradient of a horizontal line on the graph that passes through the points (2, 5) and (6, 5).

Answer: 0

Question 2: Determine whether the gradient of the line passing through (1, 3) and (4, 3) is zero. Show your working.

Answer: Yes

Question 3: On the graph, draw a line with a gradient of zero passing through the point (3, 7).

Answer: horizontal line through (3,7)

Question 4: Explain why the gradient of a vertical line is not zero.

Answer: Because the change in x is zero, making the gradient undefined, not zero.

Question 5: Calculate the gradient of the line passing through (0, 4) and (4, 4).

Answer: 0

Question 6: A line on the graph is horizontal. If the y-coordinate of the points on the line is 2, what is the gradient?

Answer: 0

Question 7: Identify the error in the following statement: 'Since the line is horizontal, its gradient must be undefined.'

Answer: The statement is incorrect because the gradient of a horizontal line is zero, not undefined.

Question 8: Plot a line on the grid with a gradient of zero passing through (5, 3).

Answer: horizontal line through (5,3)

Question 9: A graph shows a line parallel to the x-axis. The line passes through the points (x, 8) and (x+2, 8). What is the gradient of this line?

Answer: 0

Question 10: A student claims the gradient of a horizontal line is always 1. Explain whether this is correct and why.

Answer: Incorrect. The gradient of a horizontal line is 0 because there is no vertical change.

Question 11: Identify and correct the mistake in calculating the gradient between points (2, 5) and (2, 9).

Answer: The mistake is dividing by zero; the change in x is zero, so the gradient is undefined, not a number.