differentiate 1/x
To ease differentiation, the expression 1x is turned into x-1
Let's differentiate: ddx(x-1)
We differentiate using: ddx(fn) = n·ddx(f)·fn -1 (where f = x)
ⓘ The derivative of x^n is n*x^(n-1): ddx(x-1) = -1·x-2
-1·x-2
ⓘ Multiplying by -1 gives the opposite: -1·x-2 = -x-2
-x-2
ⓘ The factor is moved to the numerator or the denominator by changing the sign of its exponent, for a nonzero base: -x-2 = -1x2
▶Derivative:   -1x2