pls see the question
Answers
Answer:
Option B is correct .i.e., f(x) = 2 + x²
Step-by-step explanation:
Given: g(x) = 1 + √x
f(g(x)) = 3 + 2√x + x
To find: f(x)
Option A:
Let f(x) = 1 + 2x²
then,
f(g(x)) = 1 + 2(1 + √x)²
= 1 + 2 (1² + (√x)² + 2√x )
= 1 + 2( 1 + x + 2√x )
= 1 + 2 + 2x + 4√x
= 3 + 2x + 4√x
It not matches with given f(x).
Thus, this option is incorrect.
Option B:
Let f(x) = 2 + x²
then,
f(g(x)) = 2 + (1 + √x)²
= 2 + 1² + (√x)² + 2√x
= 2 + 1 + x + 2√x
= 3 + x + 2√x
It matches with given f(x).
Thus, this option is correct.
Option C:
Let f(x) = 1 + x
then,
f(g(x)) = 1 + (1 + √x)
= 1 + 1 + √x
= 2 + √x
It not matches with given f(x).
Thus, this option is incorrect.
Option D:
Let f(x) = 2 + x
then,
f(g(x)) = 2 + (1 + √x)
= 2 + 1 + √x
= 3 + √x
It not matches with given f(x).
Thus, this option is incorrect.
Therefore, Option B is correct.