### Home > INT3 > Chapter 1 > Lesson 1.2.2 > Problem1-90

1-90.

Think about the coordinate axes in the two-dimensional coordinate plane. What is the equation of the $x$-axis? What is the equation of $y$-axis?

What are the $y$-values for all the points on the $x$-axis?
How would you write an equation to describe that?
Make a list of several points on the $x$-axis if you need to.

Similarly, what are the $x$-values of all the points on the vertical axis?