Let $f (x) = 3^{x}$ $f(x)=3^x$ , what is the value of f(-1)?

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Answer 1 · 2018-03-10T17:58:39

See a solution process below:

To find the value of $f (- 1)$ $f(-1)$ we need to substitute $- 1$ $color(red)(-1)$ for each occurrence of $x$ $color(red)(x)$ in $f (x)$ $f(x)$

$f (x) = 3^{x}$ $f(color(red)(x)) = 3^color(red)(x)$ becomes:

$f (- 1) = 3^{- 1}$ $f(color(red)(-1)) = 3^color(red)(-1)$

$f (- 1) = \frac{1}{3^{- - 1}}$ $f(color(red)(-1)) = 1/3^color(red)(- -1)$

$f (- 1) = \frac{1}{3^{1}}$ $f(color(red)(-1)) = 1/3^color(red)(1)$

$f (- 1) = \frac{1}{3^{1}}$ $f(color(red)(-1)) = 1/3^1$

$f (- 1) = \frac{1}{3}$ $f(color(red)(-1)) = 1/3$

Let f(x)=3^xf(x)=3xf(x)=3^x, what is the value of f(-1)?