The polynomial function is
.
Step 1: Find the total number of zeros.
\Since the polynomial function
has degree
, the function has
zeros.
Step 2: Find the type of zeros.
\Examine the number of sign changes for
and
.
The possible number of positive zeros of polynomial function
is the number of sign changes of the coefficients of
or that number positive odd number.
.
Since there are
sign changes in the
the possible number of positive zeros of polynomial function
is
.

Since there are
sign changes in the
the impossible number of negative zeros of polynomial function
is
.
Hence, by Descartes
sign rule, the maximum number of zeros is
.
Step 3: Find the real zeros list some possible values and then use synthetic substitution to evaluate
for real values of
.
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The depressed polynomial is
.
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The depressed polynomial is
.
The quadratic function is
.
(Quadratic formula)
(Substitute
and
)
(Simplify)
(Subtract and simplify)
and
(Separate two roots)
and
(Simplify)
The function has two real zeros at
and
, imaginary zeros at
and
.
Check solution for
-values.
Graph:
\Graph the equation
.

Observe the graph:
\The graph cross the
- axis at
and
.
Therefore, the value of
is
and
.
The function has
number of real and imaginary zeros.
Zeroes of the function are
and
.