Question

Consider the function f(x,y) = x^{5}y - 35 x^{4} + 16807
y. Find and classify the critical point of the function.

There is a critical point at
(, )

Answer 1

For my x value I get 7, when it is suppose to be -ve 7.

Answer 2

You just messed up your sign here:
\[x^5+16807=0\]\[x^5=-16807\]\[x=(-16807)^{1/5}\]\[x=-7\]