[tex]\it \left(-\dfrac{1}{2}\right)^4 = \left(\dfrac{1}{2}\right)^4 = \dfrac{1^4}{2^4} = \dfrac{1}{16}[/tex]
Un număr negativ ridicat la o putere pară dă rezultatul pozitiv.
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[tex]\it \left(-\dfrac{1}{2}\right)^{-4} = \left[\left(-\dfrac{1}{2}\right)^4\right]^{-1} =\left[\left(\dfrac{1}{2}\right)^4\right]^{-1}= \left(\dfrac{1^4}{2^4}\right)^{-1} = \left(\dfrac{1}{16}\right)^{-1} =
\\\;\\ \\\;\\
= \dfrac{16}{1}=16[/tex]
Observație:
[tex]\it \left(\dfrac{a}{b}\right)^{-1} = \dfrac{b}{a}[/tex]
