The maximum slope of the curve

Question:

The maximum slope of the curve $y=\frac{1}{2} x^{4}-5 x^{3}+18 x^{2}-19 x$ occurs at the point

  1. $(2,2)$

  2. $(0,0)$

  3. $(2,9)$

  4. $\left(3, \frac{21}{2}\right)$


Correct Option: 1

Solution:

$\frac{\mathrm{dy}}{\mathrm{dx}}=2 \mathrm{x}^{3}-15 \mathrm{x}^{2}+36 \mathrm{x}-19$

Since, slope is maximum so,

$\frac{\mathrm{d}^{2} \mathrm{y}}{\mathrm{dx}^{2}}=6 \mathrm{x}^{2}-30 \mathrm{x}+36=0$

$y=\frac{1}{2} \times 16-5 \times 8+18 \times 4-19 \times 2$

$=8-40+72-38=80-78=2$

point $(2,2)$

Leave a comment

Close

Click here to get exam-ready with eSaral

For making your preparation journey smoother of JEE, NEET and Class 8 to 10, grab our app now.

Download Now