Math
posted by Melanie on .
1) What is the slope of a line that is parallel to y = 2?
2) What is the slope of a line that is perpendicular to y = 2?
3) What is the slope of a line that is parallel to x = 4?
4) What is the slope of a line that is perpendicular to x = 4?
I don't get any of these problems! AT ALL :/ I only know how to find the slope if the equation is in slope intercept form. Someone please help!
Give me the correct answers but also tell me how you got them so I can learn.

A line that is parallel to y = 2 has a slope of 0.
A line perpendicular to y = 2 has a slope of infinity (or undefined).
A line parallel to x = 4 has a slope of infinity (or undefined).
A line perpendicular to x = 4 has a slope of 0.
By slope intercept form I assume you mean y = mx + c.
The first equation is y = 2. It's already in slope intercept form, just simplified.
Think of it as y = 0x + 2. Now it's easier to see that the slope of such a line is 0 and the intercept is +2. This line is a horizontal line that intercepts at (0,2).
A line perpendicular to that would therefore have a slope of infinity, or an undefined slope since it's a vertical line.
The second equation is x = 4. That means that there can be no other x value anywhere on this line than 4. It's a vertical line that only crosses the x axis. Vertical = undefined slope.