The answer to your question is A
Answer:
The solutions listed from the smallest to the greatest are:
x:

y: -1 1 -1 1
Step-by-step explanation:
The slope of the tangent line at a point of the curve is:


The tangent line is horizontal when
. Then:



, for all 
, for all 
The first four solutions are:
x:

y: 1 -1 1 -1
The solutions listed from the smallest to the greatest are:
x:

y: -1 1 -1 1
The 84th day since the greatest common multiple is 84.
Please see picture above.
The answers are 1 1/6 and -1/6!