[tex]$(06.05 \, MC)$[/tex]

What is [tex]$f[g(3)]$[/tex] for the following functions?

[tex]\[
\begin{array}{l}
f(x) = 4x^2 - 3 \\
g(x) = 5x - 2
\end{array}
\][/tex]

A. [tex]$f[g(3)] = 163$[/tex]
B. [tex]$f[g(3)] = 673$[/tex]
C. [tex]$f[g(3)] = 363$[/tex]
D. [tex]$f[g(3)] = 13$[/tex]



Answer :

To solve for [tex]\( f[g(3)] \)[/tex], we need to follow these steps:

1. Determine [tex]\( g(3) \)[/tex]:
Given the function [tex]\( g(x) = 5x - 2 \)[/tex], we substitute [tex]\( x = 3 \)[/tex] into the function:

[tex]\[ g(3) = 5 \cdot 3 - 2 \][/tex]

Simplifying this:

[tex]\[ g(3) = 15 - 2 = 13 \][/tex]

Therefore, [tex]\( g(3) = 13 \)[/tex].

2. Calculate [tex]\( f[g(3)] \)[/tex] by substituting [tex]\( g(3) \)[/tex] into [tex]\( f(x) \)[/tex]:
Given the function [tex]\( f(x) = 4x^2 - 3 \)[/tex], we now need to substitute [tex]\( x = 13 \)[/tex] into [tex]\( f(x) \)[/tex]:

[tex]\[ f(13) = 4 \cdot (13)^2 - 3 \][/tex]

First, compute [tex]\( 13^2 \)[/tex]:

[tex]\[ 13^2 = 169 \][/tex]

Next, multiply by 4:

[tex]\[ 4 \cdot 169 = 676 \][/tex]

Finally, subtract 3:

[tex]\[ 676 - 3 = 673 \][/tex]

Therefore, [tex]\( f(13) = 673 \)[/tex].

3. Conclusion:
We have determined that [tex]\( f[g(3)] \)[/tex] is 673.

Thus, the correct answer is:

[tex]\[ f[g(3)] = 673 \][/tex]