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Select the correct answer.

What is the value of [tex]$g(2)$[/tex]?

[tex]g(x)=\left\{\begin{array}{ll}
\left(\frac{1}{2}\right)^{x-3}, & x\ \textless \ 2 \\
x^3 - 9x^2 + 27x - 25, & x \geq 2
\end{array}\right.[/tex]

A. [tex]\frac{1}{2}[/tex]
B. 1
C. 2
D. -1



Answer :

To find the value of [tex]\( g(2) \)[/tex] for the given piecewise function, we need to determine which part of the function to use. The function is defined as:

[tex]\[ g(x) = \begin{cases} \left(\frac{1}{2}\right)^{x-3}, & \text{if } x < 2 \\ x^3 - 9x^2 + 27x - 25, & \text{if } x \geq 2 \end{cases} \][/tex]

Here, we are asked to find [tex]\( g(2) \)[/tex]. Since [tex]\( x = 2 \)[/tex], we use the second part of the piecewise function because [tex]\( 2 \)[/tex] is greater than or equal to [tex]\( 2 \)[/tex]:

[tex]\[ g(x) = x^3 - 9x^2 + 27x - 25 \][/tex]

Substituting [tex]\( x = 2 \)[/tex]:

[tex]\[ g(2) = 2^3 - 9 \cdot 2^2 + 27 \cdot 2 - 25 \][/tex]

First, calculate each term individually:

[tex]\[ 2^3 = 8 \][/tex]
[tex]\[ 9 \cdot 2^2 = 9 \cdot 4 = 36 \][/tex]
[tex]\[ 27 \cdot 2 = 54 \][/tex]
[tex]\[ - 25 \text{ remains as it is} \][/tex]

Now, combine these results:

[tex]\[ g(2) = 8 - 36 + 54 - 25 \][/tex]

Step-by-step addition and subtraction:

[tex]\[ 8 - 36 = -28 \][/tex]
[tex]\[ -28 + 54 = 26 \][/tex]
[tex]\[ 26 - 25 = 1 \][/tex]

Therefore, the value of [tex]\( g(2) \)[/tex] is 1.

So, the correct answer is [tex]\( \boxed{1} \)[/tex].