The function is
.
To find the zeros of the function, set the equation
and multiply the equation by
.
.
.
.
.
Now the function is
.
Identify Possible Rational Zeros:
\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.
\The function is
.
Because the leading coefficient is
, the possible rational zeros are the intezer factors of the constant term
.
or
.
Therefore, the possible rational zeros of
are
.
The function is
.
Perform the synthetic division method by testing
and
.

Since
, conclude that
is a zero of
.
Therefore
is a rational zero.
The depressed polynomial is
.
Perform the synthetic division method on the depressed polynomial by testing
and
.

Since
, conclude that
is a zero of
.
Therefore
is a rational zero.
The new depressed polynomial is
.
Perform the synthetic division method on the new depressed polynomial by testing
and
.

Since
, conclude that
is a zero of
.Therefore
is a rational zero.
The remaining quadratic factor is
, which can be written as
.
The factor
yeilds no zeros.
The final quotient can be written as
.
yeilds no rational zeros.
Factoring the quadratic expression :
.
By using Factor theorem,
\When
then
is a factor of polynomial.
Factoring of
.
Zeros are
.
Rational zeros of
are
.