JEE Main202118 Mar 2021Morning ShiftMathematicsFunctionsActual
If the functions are defined as f ( x ) = x and g ( x ) = 1 - x , then what is the common domain of the following functions: f + g , f - g , f / g , g / f , g - f , where f ± g x = f x ± g x , f / g x = f ( x ) g ( x )
Options
- A0 ≤ x ≤ 1
- B0 ≤ x < 1
- C0 < x < 1
- D0 < x ≤ 1
Correct answer
C. 0 < x < 1
Step-by-step solution
f ( x ) + g ( x ) = x + 1 - x , domain 0 ,   1 f ( x ) - g ( x ) = x - 1 - x , domain 0 ,   1 g ( x ) - f ( x ) = 1 - x - x , domain 0 ,   1 f ( x ) g ( x ) = x 1 - x , domain [ 0 ,   1 ) g ( x ) f ( x ) = 1 - x x , domain ( 0 ,   1 ] So, common domain is 0 ,   1