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The maximum slope of the tangents to the curve y(x)=−x3+3x2+9x−30y(x) = -x^3 + 3x^2 + 9x - 30 is

Solution

✅ Correct Option: 2

Slope m=dydx=−3x2+6x+9m = \frac{dy}{dx} = -3x^2 + 6x + 9.

Maximize mm: dmdx=−6x+6=0\frac{dm}{dx} = -6x + 6 = 0, so x=1x = 1.

d2mdx2=−6<0\frac{d^2 m}{dx^2} = -6 < 0, confirming maximum.

m(1)=−3+6+9=12m(1) = -3 + 6 + 9 = 12.

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