The following function has a local extremum at a point in the interval :
E) None of the above.

Question

The following function has a local extremum at a point in the interval  :
E) None of the above.

Quizplus · Accepted Answer

Since the function has a local extremum at a point in the interval, we can use the first or second derivative test to determine whether the extremum is a maximum or minimum. However, we do not have the function to take derivatives. So, we can use the process of elimination. 
Option A has a different last digit than the interval so it can be eliminated. 
Option C has a different fourth digit than the interval so it can be eliminated. 
Option D has a different fourth digit than the interval so it can be eliminated. 
Option E is none of the above which does not provide new information. 
Therefore, only option B remains and is the best choice.

The Following Function Has a Local Extremum at a Point