We want to determine approximately a zero for the polynomial
-

with the help of the method given by the Intermediate value theorem. We have
and
,
hence by
fact,
there must be a zero inside the interval
. We compute the value of the function at the arithmetic mean of the interval, which is
, and get
-

Hence, we have to continue with the right half of the interval
. The arithmetic mean thereof is
. The value of the function at this point is
-

So now we have to continue with the left part of the interval, namely
. Its arithmetic mean is
. The value of the function at this point is
-

Therefore, we know that there is a zero between
and
.