The function is
.
Identify Possible Rational Zeros :
\Usually it is not practical to test all possible zeros of a polynomial function using only synthetic substitution. The Rational Zero Theorem can be used for finding the some possible zeros to test.
\
.
Possible rational zeros
.
Therefore, the possible rational zeros of
are
.
Consider
.
Perform the synthetic substitution method by testing
.

Since
, conclude that
is a zero of
.
Therefore,
is a rational zero.
The depressed polynomial is
.
The depressed polynomial
yields no rational zeros.
Therefore,
is a rational zero of
.
Therefore the possible rational zeros of
are
.
The rational zero of
is
.