differentiate 1/(x+1)
To ease differentiation, the expression 1x + 1 is turned into (x + 1)-1
Let's differentiate: ddx((x + 1)-1)
We differentiate using: ddx(fn) = n·ddx(f)·fn -1 (where f = x + 1)
ⓘ The derivative of x^n is n*x^(n-1): ddx((x + 1)-1) = -1·ddx(x + 1)·(x + 1)-2
-1·ddx(x + 1)·(x + 1)-2
ⓘ Multiplying by -1 gives the opposite: -1·ddx(x + 1)·(x + 1)-2 = -ddx(x + 1)·(x + 1)-2
-ddx(x + 1)·(x + 1)-2
ⓘ The factor is moved to the numerator or the denominator by changing the sign of its exponent, for a nonzero base: -ddx(x + 1)·(x + 1)-2 = -ddx(x + 1)(x + 1)2
-ddx(x + 1)(x + 1)2
ⓘ The derivative of a sum is the sum of the derivatives: ddx(x + 1) = 1 + 0
-1 + 0(x + 1)2
ⓘ Adding 0 changes nothing: 1 + 0 = 1
▶Derivative:   -1(x + 1)2