Question Details

If f:R→R is given by f(x)=(5+x4)1/4, then fοf(x) is

Options

A

x

B

10+x⁴

C

5+x⁴

D

(10+x⁴)¹/⁴

Correct Answer :

(10+x⁴)¹/⁴

Solution :

The correct option is (10+x⁴)¹/⁴.

Step-by-step Explanation:

We are given the function:
f ( x ) = ( 5 + x 4 ) 1 / 4

We want to find the composite function (ff)(x), which is defined as:
( f f ) ( x ) = f ( f ( x ) )

Substitute the expression for f(x) into itself:
f ( f ( x ) ) = [ 5 + ( f ( x ) ) 4 ] 1 / 4

Now, substitute f(x)=(5+x4)1/4 into the equation:
f ( f ( x ) ) = [ 5 + ( ( 5 + x 4 ) 1 / 4 ) 4 ] 1 / 4

Simplify the inner term. Since (am)n=amn, we have:
[ ( 5 + x 4 ) 1 / 4 ] 4 = ( 5 + x 4 ) 1 4 4 = 5 + x 4

Substitute this simplified term back into the expression:
f ( f ( x ) ) = [ 5 + ( 5 + x 4 ) ] 1 / 4

Combine the constant terms inside the bracket:
f ( f ( x ) ) = ( 10 + x 4 ) 1 / 4

Thus, the value of (ff)(x) is (10+x4)1/4.

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