**Note:- 1) If y = x^n ; where n = constant ; then dy/dx = n*x^(n-1)**

Now,

`f(x) = 27/x^3`

`f'(x) = -81/x^4`

``Now, slope of the graph = f'(x)

Hence slope at (3,1) = f'(3) = `-81/3^4`

`or, f'(3) = -81/81 = -1`

``

**Note:- 1) If y = x^n ; where n = constant ; then dy/dx = n*x^(n-1)**

Now,

`f(x) = 27/x^3`

`f'(x) = -81/x^4`

``Now, slope of the graph = f'(x)

Hence slope at (3,1) = f'(3) = `-81/3^4`

`or, f'(3) = -81/81 = -1`

``