Interval Notation: f(x) > 36 for x < 21

[shoook]

I am working with a linear line with positive slope, the points are given.

1. In interval notation write for which values f(x) > 36



2. At f(x)=36 x=21



3. I think it should look like (-inf,21)

 

[Dick]

Why not (21,inf)? It has POSITIVE slope.

 

[shoook]

I thought it should be -inf because it asks for all values below 21, not above... what do you think?

 

[Dick]

Looks to me like it's asking for where f(x)>36. Draw a line with positive slope and having f(21)=36.