Given [tex]f(x)=x+1[/tex] and [tex]g(x)=x^2[/tex], what is [tex](g \circ f)(x)[/tex]?

[tex]\[
\begin{array}{l}
(g \circ f)(x) = x^2 + x + 1 \\
(g \circ f)(x) = x^2 + 1 \\
(g \circ f)(x) = (x+1)^2 \\
(g \circ f)(x) = x^2(x+1)
\end{array}
\][/tex]



Answer :

To determine [tex]$(g \circ f)(x)$[/tex], we need to find the composition of the functions [tex]\( f(x) \)[/tex] and [tex]\( g(x) \)[/tex].

Given:
[tex]\[ f(x) = x + 1 \][/tex]
[tex]\[ g(x) = x^2 \][/tex]

The notation [tex]\( (g \circ f)(x) \)[/tex] means we apply [tex]\( f \)[/tex] first and then [tex]\( g \)[/tex] to the result of [tex]\( f \)[/tex]. In other words:
[tex]\[ (g \circ f)(x) = g(f(x)) \][/tex]

Step-by-step solution:
1. Start by applying [tex]\( f(x) \)[/tex]:
[tex]\[ f(x) = x + 1 \][/tex]

2. Substitute [tex]\( f(x) \)[/tex] into [tex]\( g(x) \)[/tex]:
[tex]\[ g(f(x)) = g(x + 1) \][/tex]

3. Now substitute [tex]\( x + 1 \)[/tex] into [tex]\( g(x) \)[/tex]:
[tex]\[ g(x + 1) = (x + 1)^2 \][/tex]

Therefore, the composition [tex]\( (g \circ f)(x) \)[/tex] is:
[tex]\[ (g \circ f)(x) = (x + 1)^2 \][/tex]

Among the given options, the correct one is:
[tex]\[ (g \circ f)(x) = (x + 1)^2 \][/tex]