​ If y = cot^-1(1-x/1+x) then dy/dx = ? A. -1/(1+x^2) B. 1/(1+x^2) C. -1/(1+x^2)^3/2 D. none of these ​

Question

If y = cot^-1(1-x/1+x) then dy/dx = ?

A. -1/(1+x²)

B. 1/(1+x²)

C. \(\frac{-1}{(1+x^2)^{3/2}}\)

-1/(1+x²)^3/2

D. none of these

Answer 1

Answer is: B. 1/(1+x²)

Differentiating with respect to x, we get

dy/dx = 1/(1+x²)