When y'=0, x=- 1.

x & lt- 1，y '

X>- 1, y'>0, the function is monotonically increasing.

So x=- 1 is a minimal point and a minimal point.

When x=- 1, the minimum value is-1/e, and there is no maximum value.

A point with a derivative of 0 is not necessarily an extreme point. For example, the derivative of y = x 3 is 0 at x=0, but x=0 is not an extreme point.

What you said is the right way to find the best value. If there is no restriction on the domain, there may be no optimal value. The question is.