The function .
Identify 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.
\Rational Root Theorem, if a rational number in simplest form p/q is a root of the polynomial equation , then p is a factor of a0 and q is a factor if an.
If p/q is a rational zero, then p is a factor of and q is a factor of
.
The possible values of p are ±0.
\The possible values for q are .
By the Rational Roots Theorem, the only possible rational roots are,
Make a table for the synthetic division and test possible real zeros.
\ \
p/q \ | \
\
4 \ \ \ | \
\
-5 \ | \
\
1 \ | \
\
1 \ | \
\
- 1 \ | \
\
- 1 \ | \
\
1 \ | \
\
- 3 \ | \
\
2 \ \ \ | \
1 | \1 | \
Since f(3) = 0, x = 3 is a zero. The depressed polynomial is x3 + x2 – 4x + 6 = 0.
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