We need to find y when `x = 2`.

On substituting, we have:


Solving for `y` using the quadratic formula gives:

`y^2 +2y - 4=0`

`y=(-2+- sqrt(2^2 + 16))/2`

`y=-1 +- sqrt(5)`

Now, since the question says `y > 0`, we choose `y=-1+sqrt(5)=1.236` only.

Using the result from the first part of the question:


We substitute and obtain:





Here is a movie of the solution. The form of the second derivative here is different to the above solution, but is also quite correct.