Graphs: Finding the Point of Intersection between a Line and the X-axis

The video tutorial explains how to find the point where a line perpendicular to another crosses the X-axis. It starts by introducing the problem and the equations of the lines involved. The tutorial then details the calculation of the gradient for the perpendicular line using a specific formula. It proceeds to find the Y-intercept by substituting known coordinates into the equation. The tutorial includes a visualization of the line on a graph and concludes by solving for the X-axis intersection point. Finally, it outlines the marking scheme for the problem.

What is the equation of line L1?

• y = 6 - 2x

• y = -2x + 6

• y = 6 + 2x

• y = 2x - 6

How do you find the gradient of a line perpendicular to another line with a gradient of -2?

• Take the negative reciprocal

• Add 1

• Multiply by 2

• Divide by 2

What is the gradient of line L2 if it is perpendicular to line L1 with a gradient of -2?

• 1/2

• 2

• -2

• -1/2

Given that line L2 passes through the point (4,7), what is the y-intercept of line L2?

• 4

• 7

• 5

• 3

What is the equation of line L2 after finding the y-intercept?

• y = -1/2x - 5

• y = 1/2x - 5

• y = 1/2x + 5

• y = -1/2x + 5

How do you find the X-intercept of a line?

• Set y to 0

• Set x to 0

• Set the y-intercept to 0

• Set the gradient to 0

What are the coordinates where line L2 crosses the X-axis?

• (0, 10)

• (-10, 0)

• (10, 0)

• (0, -10)