Which expression is equivalent to [tex]$(s t)(6)$[/tex]?

A. [tex]$s(t(6))$[/tex]
B. [tex]$s(x) \cdot t(6)$[/tex]
C. [tex][tex]$s(6) \cdot t(6)$[/tex][/tex]
D. [tex]$6 \cdot s(x) \cdot t(x)$[/tex]



Answer :

Let's evaluate each of the given expressions step-by-step to see which one is equivalent to [tex]\((s \circ t)(6)\)[/tex].

First, understand that [tex]\((s \circ t)(x)\)[/tex] means [tex]\(s(t(x))\)[/tex], which represents applying the function [tex]\(t\)[/tex] on [tex]\(x\)[/tex] first, and then applying the function [tex]\(s\)[/tex] on the result of [tex]\(t(x)\)[/tex].

Given that [tex]\(s\)[/tex] and [tex]\(t\)[/tex] are identity functions for any input [tex]\(x\)[/tex]:
[tex]\[ s(x) = x \][/tex]
[tex]\[ t(x) = x \][/tex]

Let's evaluate the expressions one by one:

1. [tex]\(s(t(6))\)[/tex]:
[tex]\[ s(t(6)) = s(6) = 6 \][/tex]
So, this expression equals 6.

2. [tex]\(s(x) \cdot t(6)\)[/tex]:
[tex]\[ s(x) \cdot t(6) = s(6) \cdot 6 = 6 \cdot 6 = 36 \][/tex]
So, this expression equals 36.

3. [tex]\(s(6) \cdot t(6)\)[/tex]:
[tex]\[ s(6) \cdot t(6) = 6 \cdot 6 = 36 \][/tex]
So, this expression equals 36.

4. [tex]\(6 \cdot s(x) \cdot t(x)\)[/tex]:
[tex]\[ 6 \cdot s(6) \cdot t(6) = 6 \cdot 6 \cdot 6 = 216 \][/tex]
So, this expression equals 216.

After evaluating all the expressions, it's clear that the expression equivalent to [tex]\((s \circ t)(6)\)[/tex] is:

[tex]\[ s(t(6)) = 6 \][/tex]

Therefore, the correct expression is:
[tex]\[ s(t(6)) \][/tex]