Question
Real Analysis Question on Functions of One Real Variable
Consider the function f: ℝ → ℝ given by f(x) = x3 - 4x2 + 4x - 6.
For c ∈ ℝ, let
S(c)=\left\\{x \in \R : f(x)=c\right\\}
and |S(c)| denote the number of elements in S(c). Then, the value of
|S(-7)| + |S(-5)| + |S(3)|
equals _________
Answer
The correct answer is 5.