(Explanation: We are given that the curve
passes through the point
. Near this point, the curve is the graph of a function,
. When
,
.)
is the same thing as
evaluated at the point
. In order to find this, we use implicit differentiate the equation
with respect to
.
In order to solve for
, we first factorize,
Then subtract
from both sides and divide by
to obtain
When
Hence,
.