How do you state the domain and range of #f(x)=x^2-2#?

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Answer 1 · 2017-02-09T14:01:30

The domain of #f(x)# is #D_f(x)=RR#
The range is #y in [-2, +oo[#

#f(x)# is a polynomial function

The domain of #f(x)# is #D_f(x)=RR#

Let #y=x^2-2#

#x^2=y+2#

#x=sqrt(y+2)#

So,

#f^-1(x)=sqrt(x+2)#

The domain of #f^-1(x)# is the range of #f(x)#

Therefore,

#x+2>=0#

#x >=-2#

The range is #y in [-2, +oo[#