Given the equation _{}=0, find the values of k such that one root of the equation
is less than 1; another root is in the interval (1, 4); and the third root is
greater than 4.

[Problem
submitted by Steve Lee, LACC Professor of Mathematics.]

**Solution for Problem 7:**

Let f(x)= _{}, then a rough sketch of the graph of f(x) is the following.

(1) _{}or _{}

(2)

_{}_{}

k must satisfy both (1) and (2).

_{}