GCSE Secondary Maths Age 13-17 - Graphs: Equation of a straight line - Explained

The video tutorial explains how to find the equation of a line perpendicular to a given line N that passes through a specific point. It covers the concept of gradients, particularly how to calculate the gradient of line N using a right-angled triangle. The tutorial then explains how to find the gradient of a perpendicular line by taking the reciprocal and changing the sign. Finally, it derives the equation of the new line using the y-intercept and discusses the marking scheme for the problem.

What is the first step in finding the equation of a line perpendicular to another line?

• Calculate the length of the original line.

• Find the midpoint of the original line.

• Determine the gradient of the original line.

• Identify the y-intercept of the original line.

How do you calculate the gradient of a line using a right-angled triangle?

• By dividing the change in y by the change in x.

• By multiplying the change in x by the change in y.

• By adding the change in x and the change in y.

• By dividing the change in x by the change in y.

What is the gradient of a line perpendicular to a line with a gradient of 3?

• -3

• -1/3

• 3

• 1/3

What is the correct method to find the gradient of a line perpendicular to another line?

• Take the reciprocal of the original gradient and change its sign.

• Subtract 1 from the gradient of the original line.

• Double the gradient of the original line.

• Add 1 to the gradient of the original line.

If a line passes through the point (0, 1), what is its y-intercept?

• 0

• 1

• -1

• It cannot be determined.