CPM Homework Banner

Home > A2C > Chapter 7 > Lesson 7.1.2 > Problem 7-21

7-21.
  1. For each of the following equations, find every point where its three-dimensional graph intersects one of the coordinate axes. That is, find the x-, y- and z-intercepts. Express your answer in (x, y, z) form. 7-21 HW eTool (CPM). Homework Help ✎

    1. 6y + 15z = 60

    2. 3x + 4y + 2z = 24

    3. (x + 3)2 + z2 = 25

    4. z = 6

To find the intercept of a given axis, set all other variables to zero.
For example, the y-intercept will be (0, ?, 0).
To find the y-intercept, let x = 0 and z = 0

Repeat the process to find the z-intercept. (0, 0, ?).

(0, 10, 0) and (0, 0, 4)

See part (a):

See part (a).
Note: You will have two x-intercepts and two z-intercepts. Why?

See part (a):

Use the eTool below to test your solutions to parts (a), (b) and (c) above.
Click the link at right for the full version of the eTool: A2C 7-21 HW eTool