Question

Which is a stretch of an exponential decay function? f(x) = Four-fifths (five-fourths) Superscript x f(x) = Four-fifths (four-fifths) Superscript x f(x) = Five-fourths (four-fifths) Superscript x f(x) = Five-fourths (five-fourths) Superscript x

Answer 1

Answer:

Options 2 and 3 are correct.

Step-by-step explanation:

The general form of an exponential decay function is $f(x) = a(b)^{x}$ where b < 1.

Now, the four exponential functions are:

(i) $f(x) = \frac{4}{5}(\frac{5}{4} )^{x}$ is not an exponential decay function as $\frac{5}{4} > 1$.

(ii) $f(x) = \frac{4}{5}(\frac{4}{5} )^{x}$ is an exponential decay function as $\frac{4}{5} < 1$.

(iii) $f(x) = \frac{5}{4}(\frac{4}{5} )^{x}$ is an exponential decay function as $\frac{4}{5} < 1$.

(iv) $f(x) = \frac{5}{4}(\frac{5}{4} )^{x}$ is not an exponential decay function as $\frac{5}{4} > 1$.

So, options 2 and 3 are correct. (Answer)

Answer 2

Answer:

2

Step-by-step explanation:

B