Answer
Makes sense.
Work Step by Step
1. To check if a function is odd or even we check if
$ f(-x)=-f(x)\qquad$ (odd)
$ f(-x) =f(x)\qquad$ (even)
(we do check $f(-x)$ )
2. Using Descartes's Rule of Signs (page 384),
we estimate the number of negative real roots by
counting the number of sign changes in the expression of $f(-x)$
So, yes, this makes sense.
