derivative of (arctan(x))^2
Let's differentiate: ddx(arctan(x)2)
Apply the differentiation rule: ddx(fn) = n·ddx(f)·fn -1 with f = arctan(x)
ⓘ The derivative of x^n is n*x^(n-1): ddx(arctan(x)2) = 2·ddx(arctan(x))·arctan(x)
2·ddx(arctan(x))·arctan(x)
ⓘ The derivative of arctan(x) is 1/(1 + x^2): ddx(arctan(x)) = 1x2 + 1
2·1x2 + 1·arctan(x)
ⓘ Multiplying a fraction by a term multiplies its numerator: 2·1x2 + 1·arctan(x) = 2·1·arctan(x)x2 + 1 = 2·arctan(x)x2 + 1
▶Derivative:   2·arctan(x)x2 + 1