College

Given the functions [tex]f(x) = 3x^2 - 7[/tex] and [tex]g(x) = x^3 + 1[/tex], evaluate [tex]f(g(2))[/tex].

A. 45
B. 145
C. 326
D. 236

Answer :

To solve the problem of evaluating [tex]\( f(g(2)) \)[/tex] given the functions [tex]\( f(x) = 3x^2 - 7 \)[/tex] and [tex]\( g(x) = x^3 + 1 \)[/tex], we will follow these steps:

1. Evaluate [tex]\( g(2) \)[/tex]:

First, we need to find [tex]\( g(2) \)[/tex]. The function [tex]\( g(x) = x^3 + 1 \)[/tex]. Substituting [tex]\( x = 2 \)[/tex] into this function gives us:

[tex]\[
g(2) = 2^3 + 1
\][/tex]

Calculate [tex]\( 2^3 \)[/tex], which is:

[tex]\[
2^3 = 8
\][/tex]

Add 1 to 8:

[tex]\[
8 + 1 = 9
\][/tex]

So, [tex]\( g(2) = 9 \)[/tex].

2. Substitute [tex]\( g(2) \)[/tex] in [tex]\( f(x) \)[/tex]:

Now that we know [tex]\( g(2) = 9 \)[/tex], we substitute this value into the function [tex]\( f(x) \)[/tex].

The function given is [tex]\( f(x) = 3x^2 - 7 \)[/tex]. We replace [tex]\( x \)[/tex] with 9:

[tex]\[
f(9) = 3(9^2) - 7
\][/tex]

Calculate [tex]\( 9^2 \)[/tex], which is:

[tex]\[
9^2 = 81
\][/tex]

Multiply 81 by 3:

[tex]\[
3 \times 81 = 243
\][/tex]

Subtract 7 from 243:

[tex]\[
243 - 7 = 236
\][/tex]

Thus, [tex]\( f(g(2)) = f(9) = 236 \)[/tex].

Therefore, the value of [tex]\( f(g(2)) \)[/tex] is 236.