What is the domain and range of $3sqrt( x^2 - 9)$ ?

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Answer 1 · 2016-02-09T07:01:17

Domain: $x<=-3$ or $x>=3$ also Domain: $(-oo,-3] uu [3, oo)$
Range: $[0, +oo)$

x can take on values -3 or less up to $-oo$
also x can take on values 3 or higher up to $+oo$

that is why Domain : $x<=-3$ or $x>=3$

The lowest possible value is 0 up to $+oo$ and that is the range .
That is if we let

$y=3*sqrt(x^2-9)$

when $x=+-3$ the value of $y=0$ and when $x$ approaches a very high value, the value of $y$ approaches a very high value also.

So the Range: $[0, +oo)$

What is the domain and range of 3sqrt( x^2 - 9)3sqrt( x^2 - 9)?