Given the expression:
[tex] \displaystyle \large{ \sqrt[3]{ - 125} }[/tex]
Definition:
[tex] \displaystyle \large{ y = \begin{cases} \pm \sqrt[n]{x} \longrightarrow n = (2,4,6,8,...) \: \: (x \geqslant 0) \\ \sqrt[n]{x}\longrightarrow n = (1,3,5,7,...) \: \: (x \in \R) \end{cases}}[/tex]
First, factor the -125. -125 comes from (-5)×(-5)×(-5) or (-5)^3.
[tex] \displaystyle \large{ \sqrt[3]{ ( - 5) \times ( - 5) \times ( - 5)} }[/tex]
Because if (-5)^2 = 25 then 25×(-5) again will be -125.
Since this is the cube root, we have to pull out 3 terms in one. There are 3 fives that we can take off and therefore,
[tex] \displaystyle \large \boxed{ - 5}[/tex]
