10: Derivative is
Critical points: f = 0 for x equal to plus or minus root of 2; there are no points in D( f ) where f ′ does not exist.
Local maximum f at root of 2 with value 2; local minimum f at minus root of 2 with value −2.
Remark: One-sided derivatives at endpoints ate
Now determine concavity using f ′′.
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