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

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Answer 1 · 2017-02-09T14:01:30

The domain of $f (x)$ $f(x)$ 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 $y in [-2, +oo[$

How do you state the domain and range of f(x)=x^2-2f(x)=x2−2f(x)=x^2-2?