Maximum slope of the curve \(y=-2x^{3}+6x^{2}+5x-20\) is :
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → 11
The slope of the curve at any point is
\( \displaystyle m = \frac{dy}{dx} = -6x^2 + 12x + 5 \)
At the maximum of the slope, the derivative of m is zero:
\( \displaystyle \frac{dm}{dx} = -12x + 12 = 0 \)
\(x = 1\)
\( \displaystyle \frac{d^2m}{dx^2} = -12 \lt 0 \)
So the slope is greatest at x = 1:
\(m(1) = -6 + 12 + 5 = 11\)