Hi, can someone explain to me how we got derivative -1/4 for the last example in the derivatives video.

If J(w) = 1/w, then how do we get to -1/4. Is this the quotient rule? Or perhaps this is the power rule applied to fractions? Where did the negative come from?

I understand how we got to that answer arithematically with epsilon as J(w) = 1/2.001, but can we quickly calculate this with a power or quotient rule like in the previous examples?