JEE Main 202126 FebruaryMorning Shift
- Exam
- JEE Main
- Year
- 2021
- Date
- 26 February
- Shift
- Morning Shift
- Subject
- Mathematics
- Chapter
- Application of Derivatives
JEE Main 2021 · 26 February · Morning Shift · Mathematics · Application of Derivatives
The maximum slope of the curve y = (1)/(2) x ^ 4 - 5 x ^ 3 + 18 x ^...
The maximum slope of the curve occurs at the point
Options
- A
- B
- C
- D
Correct answer
B.
Step-by-step solution
\dfrac{dy}{dx} = 2{x}^{3} - 15{x}^{2} + 36x - 19\dfrac{{d}^{2}y}{d{x}^{2}} = 6{x}^{2} - 30x + 36 = 0⇒ {x}^{2} - 5x + 6 = 0x = 2, 3x = 2\dfrac{{d}^{3}y}{d{x}^{3}} = 12x - 30x = 2, \dfrac{{d}^{3}y}{d{x}^{3}} < 0y = \dfrac{1}{2} \times 16 - 5 \times 8 + 18 \times 4 - 19 \times 2= 8 - 40 + 72 - 38 = 80 - 78 = 2