Question

How do you differentiate `1/x^-0.4`?

Answer 1

`1/x^-0.4`
`=x^0.4` [reciprocal]

therefore by power rule
`dy/dx = 0.4x^(0.4-1)`
`dy/dx = 0.4x^-0.6`
which can be rewritten as
`dy/dx=0.4/x^0.6`
or
`dy/dx = 2/(5x^(3/5))`