Answered

Which of the following is a function equivalent to [tex]f(x)=5(1.9)^{3x}[/tex]?

A. [tex]f(x)=34.29^x[/tex]
B. [tex]f(x)=5(6.86x)[/tex]
C. [tex]f(x)=5(6.86)^x[/tex]
D. [tex]f(x)=328.51^x[/tex]



Answer :

We need to determine which of the following functions is equivalent to [tex]\( f(x) = 5(1.9)^{3x} \)[/tex]:

1. [tex]\( f(x) = 34.29^x \)[/tex]
2. [tex]\( f(x) = 5(6.86 x) \)[/tex]
3. [tex]\( f(x) = 5(6.86)^x \)[/tex]
4. [tex]\( f(x) = 328.51^x \)[/tex]

To do this, we will examine whether each function can be transformed into the form of [tex]\( f(x) = 5(1.9)^{3x} \)[/tex].

Let’s take a look at each function one by one:

1. [tex]\( f(x) = 34.29^x \)[/tex]

To compare this with [tex]\( f(x) = 5(1.9)^{3x} \)[/tex], observe the base of the exponent. Clearly, [tex]\( 34.29 \)[/tex] is not obviously related to [tex]\( 1.9 \)[/tex]. Therefore, this function does not match.

2. [tex]\( f(x) = 5(6.86 x) \)[/tex]

This function is not an exponential function but rather a linear function multiplied by a constant. The form is not equivalent to [tex]\( 5(1.9)^{3x} \)[/tex].

3. [tex]\( f(x) = 5(6.86)^x \)[/tex]

To see if this function is equivalent, we can compare exponents:

[tex]\[ f(x) = 5(1.9)^{3x} \][/tex]

Let’s rewrite [tex]\( (1.9)^{3x} \)[/tex] as [tex]\((1.9^3)^x\)[/tex]:

[tex]\[ f(x) = 5(1.9^3)^x \][/tex]

Now, calculate [tex]\( 1.9^3 \)[/tex]:

[tex]\[ 1.9^3 = 1.9 \times 1.9 \times 1.9 \approx 6.859 \][/tex]

Therefore, we get:

[tex]\[ f(x) = 5(6.86)^x \][/tex]

This matches our given function exactly.

4. [tex]\( f(x) = 328.51^x \)[/tex]

Similar to the first function, the base [tex]\( 328.51 \)[/tex] is not obviously related to [tex]\( 1.9 \)[/tex].

Based on these examinations, the function equivalent to [tex]\( f(x) = 5(1.9)^{3x} \)[/tex] is:

[tex]\( f(x) = 5(6.86)^x \)[/tex]

Therefore, the correct answer is:
[tex]\( f(x) = 5(6.86)^x \)[/tex]