MHT CET202312 May 2023Morning ShiftMathematicsApplication of DerivativesActual
The function f (x)= ^4 x+ ^4 x is increasing in
Options
- A0 < x < 8
- B4 < x < 2
- C3 8 < x < 5 8
- D5 8 < x < 3 4
Correct answer
B. 4 < x < 2
Step-by-step solution
aligned f (x) & = ^4 x+ ^4 x f ^ (x) & =4 ^3 x x-4 ^3 x x & =4 x x ( ^2 x- ^2 x ) & =+2 2 x 2 x & =- 4 x aligned If f (x) is increasing, then f ^ (x)>0 i.e., aligned - 4 x>0 & < 4 x < 2 & 4 < x < 2 aligned