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
.
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 .
Finding Rational Zeros :
\The depressed polynomial is .
Find the rational zeros use the quadratic formula .
Consider .
Where .
Substiute the values in the quadratic formula .
The zeros of the depressed polynomial are .
Therefore and
are the two factors.
Therefore, and
are the factors of
.
By using Factor theorem,
\When then
is a factor of polynomial.
Factor of .
So has three real zeros.
Zeros are .
The correct answer is .