An investment of \$2,500 doubles in value every 15 years. The function f defined by f(x) = 2, 500(2 ^ (rx)) represents the value of the investment , in dollars, years after the investment is made , where r is a constant. What is the value of r? R =

Respuesta :

Answer:

[tex]\dfrac{1}{15}[/tex]

Step-by-step explanation:

Given that:

Investment amount = $2500

Time in which it gets doubled = 15 years

Amount after 15 years = $5000 (As per given statement as it gets doubled)

Value of investment in dollars after [tex]x[/tex] years if investment:

[tex]f(x) = 2, 500(2 ^ {rx})[/tex]

[tex]r[/tex] is a constant.

To find:

Value of [tex]r[/tex].

Solution:

We are given that:

[tex]f(x) =\$5000[/tex]

[tex]x=15\ years[/tex]

Putting all the values in the given equation:

[tex]5000 = 2500(2 ^ {r\times 15})\\\Rightarrow 2 = 2 ^ {r\times 15}\\\Rightarrow r\times 15=1\\\Rightarrow r =\bold{\dfrac{1}{15}}[/tex]

Therefore, the value of [tex]r[/tex] is:

[tex]\dfrac{1}{15}[/tex]

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