Bounds on zeros :
\Let denote a polynomial function whose leading coefficient is
.
A bound on the real zeros of
is the smaller of the two numbers.
.
Where means " choose the largest entry in
".
The polynomial function is .
First write so that it is the product of a constant times a polynomial whose leading coefficient is
by factoring out the leading coefficient of
,
.
Evaluate the two expressions .
Consider .
Compare the above polynomial with .
, and
.
The smaller of the two numbers, , is the bound.
Every real zero of lies between
and
.
The Theorem on Bounds of Zeros tells that every zero is between and
.
Draw a coordinate plane.
\Graph the polynomial function using
.
Observe the above graph :
\The function has exactly one positive
- intercept at
.
Thus, the positive real zero is .
The positive real zero is .
\
\