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 calculation of the gradient of line N using a right-angled triangle, determining the gradient of the perpendicular line by finding the reciprocal and changing the sign, and formulating the final equation using the y-intercept. The tutorial also discusses the allocation of marks for each step in solving the problem.

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

• Find the midpoint of the original line

• Calculate the length 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 subtracting the change in x from the change in y

• By adding the changes in x and y

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

• By measuring the hypotenuse

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

• -1/3

• 1/3

• -3

• 3

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

• Subtract 1 from the original gradient

• Add 1 to the original gradient

• Take the reciprocal and change the sign

• Double the original gradient

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

• It cannot be determined

• 1

• 0

• -1