June 26, 2019

Chapters

The intercept form of the line is the equation of the line segment based on the intercepts with both axes.

**a** is the x-intercept.

**b** is the y-intercept.

**a** and **b** must be nonzero.

The values of **a** and **b** can be obtained from the general form equation.

If y = 0, x = a.

If x = 0, y = b.

A line does not have an intercept form equation in the following cases:

1.A line parallel to the x-axis, which has the equation y = k.

2.A line parallel to the x-axis, which has the equation x = k.

3.A line that passes through the origin, which has equation y = mx.

## Example 1.

A line has an x-intercept of 5 and a y-intercept of 3. Find its equation.

## Example 2.

The line x − y + 4 = 0 forms a triangle with the axes. Determine the area of the triangle.

The line forms a right triangle with the origin and its legs are the axes.

If y = 0 x = **−4 = a**.

If x = 0 y = **2 = b**.

The intercept form is:

The area is:

## Example 3.

A line passes through the point A = (1, 5) and creates a triangle of 18 u² with the axes. Determine the equation of the line.

Apply the intercept form:

The area of the triangle is:

Solve the system:

## Example 4.

A line forms a triangle with the axes where the length of the leg formed by the x-axis is twice the length of the leg formed by the y-axis. If the line passes through the point A = (3, 2), what is its equation?