MHT CET202616 April 2026Morning ShiftMathematicsApplication of DerivativesActual
The function f(x) = ⁻¹( x + x) is an increasing function in the interval.....
Options
- A(0, 2 )
- B( - 2 , 2 )
- C( 4 , 2 )
- D( - 2 , 4 )
Correct answer
D. ( - 2 , 4 )
Step-by-step solution
Given f(x) = ⁻¹( x + x) Differentiating with respect to x , we get: f'(x) = 1 1 + ( x + x)^2 d dx ( x + x) f'(x) = x - x 1 + ( x + x)^2 For f(x) to be an increasing function, f'(x) > 0 . Since the denominator 1 + ( x + x)^2 is always positive for all real x , the sign of f'(x) depends entirely on the numerator. x - x > 0 x > x From the standard trigonometric graphs, the inequality x > x holds true in the interval ( - 2 , 4 ) . Therefore, the function is increasing in the interval ( - 2 , 4 ) . Answer: ( - 2 , 4 )