If I had

Would be 2 if the value of x is 4? I worked this out on paper I think it is right but need to be sure, because the next part of the question asked to find the equation of the normal.

I found the gradient of the normal to be but the y-coordinate (when inserting 4 into the original equation) to be 42, which is a very strange value. I feel I've made a mistake somewhere along the line.

Equation of the normal from my working was therefore (in the form of )

Can anyone see a problem in this?