Tutor profile: Costa K.
When $$\log f(x)=0$$, what can you say about the function $$f(x)$$?
The function is equal to the constant function $$f(x)=1$$.
Does a function $$f(x)$$ have local minimum or local maximum at $$ \alpha $$ when its derivative is zero ?
When the derivative of a function $$f(x)$$ is zero, the function may have a local minimum or local maximum or in some cases a "turning" point.
When do we calculate the z statistic versus the t statistic from a given sample of size n?
When the standard deviation of the population is given, then we use the z statistic.