- #1
mikeyBoy83
I'm trying to understand image and pre image better but I am having a hard time finding good examples.
So here is one I did come across, let's say ##f:\mathbb{R} →\mathbb{R}## defined by ##f(x)=x^{2}##. Suppose also that ##D = [-1,2]## where ##D\subset \mathbb{R}##. If I'm looking for ##f^{-1}(D)## then I can only use ##D\setminus [-1,0)## in which case ##f^{-1}(D)=[-\sqrt{2},\sqrt{2}]##correct?
So here is one I did come across, let's say ##f:\mathbb{R} →\mathbb{R}## defined by ##f(x)=x^{2}##. Suppose also that ##D = [-1,2]## where ##D\subset \mathbb{R}##. If I'm looking for ##f^{-1}(D)## then I can only use ##D\setminus [-1,0)## in which case ##f^{-1}(D)=[-\sqrt{2},\sqrt{2}]##correct?
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