For each of the following polynomial functions, (a) use Descartes’s Rule of Signs to determine
the possible numbers of positive and negative real zeros of f, (b) list the possible rational zeros of
f, (c) use your graphing calculator to graph f to eliminate some of the possible zeros and then (d)
determine all the real zeros of f.
3
2
4. ( ) =
+
− 4 − 4
4
3
2
5. ( ) = −2
+ 13
− 21
+ 2 + 8
2
2
6. ( ) = 4
− 17
+ 4