Equation of a Straight Line and Writing Equations for Horizontal and Vertical Lines

The video tutorial explains how to write equations for vertical and horizontal lines, emphasizing their intersections with the x-axis and y-axis. It introduces the y=mx+c formula for straight lines, detailing the roles of the gradient (m) and y-intercept (c). The tutorial covers calculating the gradient by examining changes in y and x, and demonstrates deriving line equations from given coordinates.

What is the equation of a horizontal line that passes through the y-axis at -5?

• y = -5

• x = -5

• x = 5

• y = 5

In the equation y = mx + c, what does the 'm' represent?

• The y-intercept

• The x-intercept

• The constant term

• The gradient

How do you calculate the gradient of a line?

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

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

• By adding the change in y to the change in x

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

If a line has a gradient of 2 and passes through the point (3, 8), what is the y-intercept?

• 8

• 6

• 4

• 2

What is the equation of a line with a gradient of 2 and a y-intercept of 2?

• y = 2x + 2

• y = x - 2

• y = 2x - 2

• y = x + 2