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I answered a problem for my prep guide, I just need to know if I’m correct or not. And I would like it to be answered as well just to make sure that I did everything correctly

I answered a problem for my prep guide, I just need to know if I’m correct or not-example-1
User Chase
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1 Answer

2 votes

Notice that,


f(x)=3^(x-1)-6=3^x\cdot3^(-1)-6=(3^x)/(3)-6

And there are no restrictions for the values that x can take. The domain is the whole set of real numbers.

Now, we need to check for the limits when x->+/- infinite, as follows:


\begin{gathered} \lim _(x\to\infty)3^x=\infty \\ \lim _(x\to-\infty)3^x=\lim _(x\to\infty)(1)/(3^x)=0 \end{gathered}

Then, the range of 3^x is (0, infinite).

Finally, we can get the range of function f(x):


\lim _(x\to\infty)f(x)=(1)/(3)(\lim _(x\to\infty)3^x)-6=(1)/(3)\infty-6=\infty
\lim _(x\to-\infty)f(x)=(1)/(3)(\lim _(x\to-\infty)3^x)-6=(1)/(3)\cdot0-6=-6

Then,


\begin{gathered} The\text{ range of }f(x)\text{ is} \\ Range=(-6,\infty) \end{gathered}

User Murlidhar Fichadia
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4.5k points