We are asked to use the linear approximation of
at the point
to approximate
. This linear approximation, which we denote by
, is given by
. We already know that
, so we need only find
. To do so, we apply the power rule, and find that
.
Substituting this information into our formula for
, we have
. Then, to estimate the value of
, we plug in
into our linear approximation. This gives
.