derivative of 1/(1+sin(x))
To ease differentiation, the expression 11 + sin(x) is turned into (1 + sin(x))-1
Let's perform the differentiation: ddx((1 + sin(x))-1)
We differentiate using: ddx(fn) = n·ddx(f)·fn -1 (where f = 1 + sin(x))
ⓘ The derivative of x^n is n*x^(n-1): ddx((1 + sin(x))-1) = -1·ddx(1 + sin(x))·(1 + sin(x))-2
-1·ddx(1 + sin(x))·(1 + sin(x))-2
ⓘ Multiplying by -1 gives the opposite: -1·ddx(1 + sin(x))·(1 + sin(x))-2 = -ddx(1 + sin(x))·(1 + sin(x))-2
-ddx(1 + sin(x))·(1 + sin(x))-2
ⓘ The factor is moved to the numerator or the denominator by changing the sign of its exponent, for a nonzero base: -ddx(1 + sin(x))·(1 + sin(x))-2 = -ddx(1 + sin(x))(1 + sin(x))2
-ddx(1 + sin(x))(1 + sin(x))2
ⓘ The derivative of a sum is the sum of the derivatives: ddx(1 + sin(x)) = 0 + ddx(sin(x))
-0 + ddx(sin(x))(1 + sin(x))2
ⓘ Adding 0 changes nothing: 0 + ddx(sin(x)) = ddx(sin(x))■The derivative of sin(x) is cos(x): ddx(sin(x)) = cos(x)
-cos(x)(1 + sin(x))2
▶Derivative:   -cos(x)(sin(x) + 1)2