JEE Main202429 Jan 2024Evening ShiftMathematicsApplication of DerivativesActual
The function f x = 2 x + 3 x 2 3 , x ∈ R , has
Options
- Aexactly one point of local minima and no point of local maxima
- Bexactly one point of local maxima and no point of local minima
- Cexactly one point of local maxima and exactly one point of local minima
- Dexactly two points of local maxima and exactly one point of local minima
Correct answer
C. exactly one point of local maxima and exactly one point of local minima
Step-by-step solution
Given: f ( x ) = 2 x + 3 ( x ) 2 3 ⇒ f ' x = 2 + 2 x - 1 3 ⇒ f ' x = 2 1 + 1 x 1 3 ⇒ f ' x = 2 x 1 3 + 1 x 1 3 The function changes from positive to negative at x = 1 and from negative to positive at x = 0 So, the point of local maxima M is at x = - 1 and the point of local minima m at x = 0