At what points, the slope of the curve `y=-x^3+3x^2+9x-27` at point `(x ,\ \ y)` is given by maximum slope.

Explanation

To find the points at which the slope of the curve \( y = -x^3 + 3x^2 + 9x - 27 \) is maximum, we will follow these steps:

### Step 1: Differentiate the function to find the slope
The slope of the curve is given by the first derivative of \( y \) with respect to \( x \).

\[ \frac{dy}{dx} = \frac{d}{dx}(-x^3 + 3x^2 + 9x - 27) \]
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