Precalculus (6th Edition)

$f\left( x\right) =x\cos x\Rightarrow f\left( -x\right) =\left( -x\right) \times \cos \left( -x\right) =\left( -x\right) \times \cos x=-x\cos x\Rightarrow f\left( -x\right) =-f\left( x\right)$ So the equation is odd.