# Rational Functions

# Algebra II Terms

## Get down with the lingo

### Asymptote

Closer and closer and closer…a line that a graph approaches but never touches.### Combined Variation

Combines or merges direct variation (one goes up the other goes up) and inverse variation (one goes up the other goes down).### Domain

"D" is for domain, where the denominator doesn't equal diddly (by that, we mean the denominator isn't zero).### Direct Variation

An equation with a constant (*k*) where one goes up, the other goes up, or one goes down, the other goes down.

*y*=

*kx*

### Extraneous Root

A false solution to an equation. It makes the equation blow up because the denominator is zero.### Intercept

For all you sports nuts—think football. It's the point where a graph "takes," "seizes," or "crosses" an axis.### Inverse Variation

An equation with a constant (*k*) where one goes up, the other goes down, or one goes down, the other goes up.

### Joint Variation

Joint = together. It's an equation with a constant (*k*) where one depends on two variables together.

*z*=

*kxy*