Problem:

a) find the extremes and classify them.

b) now, Calculate the highest and lowest f(x,y)

Skärmavbild 2012-09-11 kl. 19.42.48.png

Attempt:

a)

2012-09-11 19.39.20.jpg

b)

2012-09-11 19.39.50.jpg

The thing is this: the anser is that x = -√17 is also an alternative. But I got x = 8/3 och x = -2.