derivative of y=3+(12)/(2-x)
We save the definition: y = 3 + 122 -x
To ease differentiation, the expression 122 -x is turned into 12·(2 -x)-1
Let's perform the differentiation: ddx(3 + 12·(2 -x)-1)
0 + ddx(12·(2 -x)-1)
Apply the differentiation rule: ddx(fn) = n·ddx(f)·f(n -1) with f = 2 -x
12·(-1·ddx(2 -x)·(2 -x)-2)
ℹ12·(-1) = -12‖ddx(2 -x) = 0 + ddx(-x)
-12·(0 + ddx(-x))·(2 -x)-2
-12·ddx(-x)(2 -x)2
-12·(-1)(2 -x)2
--12(2 -x)2
▶Derivative:   12(2 -x)2