Five: Solution (Calculus)
Find the positive value of
x for which S is a minimum. What is the corresponding minimum value?
the derivative of S with respect to x.
Set the derivative equal to zero and solve for x.
Since x must positive, disregard the solution x = 1.
is decreasing to the left of 1)
is increasing to the right of 1)
x = 1 corresponds to a minimum.
S has a minimum value of 2 when x is 1.
x=-1, what can you say about S?