A rational function in this case needs a non-constant denominator. Thus something like $\frac {x+1}{4}$ would not be considered a rational function (mostly because we can rewrite it as $\frac {1}{4}x + \frac {1}{4}$, a polynomial). However, a rational function can have a constant numerator, thus $\frac {1}{x+1}$ would be considered a rational function.

A rational function in this case needs a non-constant denominator. Thus something like $\frac {x+1}{4}$ would not be considered a rational function (mostly because we can rewrite it as $\frac {1}{4}x + \frac {1}{4}$, a polynomial). However, a rational function can have a constant numerator, thus $\frac {1}{x+1}$ would be considered a rational function.

A rational function in this case needs a non-constant denominator. Thus something like $\frac {x+1}{4}$ would not be considered a rational function (mostly because we can rewrite it as $\frac {1}{4}x + \frac {1}{4}$, a polynomial). However, a rational function can have a constant numerator, thus $\frac {1}{x+1}$ would be considered a rational function.

A rational function in this case needs a non-constant denominator. Thus something like $\frac {x+1}{4}$ would not be considered a rational function (mostly because we can rewrite it as $\frac {1}{4}x + \frac {1}{4}$, a polynomial). However, a rational function can have a constant numerator, thus $\frac {1}{x+1}$ would be considered a rational function.

Remember that a rational function needs to be a (as in singular) ratio of functions. We can combine these fractions into a single fraction by using common denominators and the like, but as given it is the sum of several rational functions, and thus not a rational function itself.