Hello everyone. I need help on the following problem involving inverse trig.

A) Show that the derivative of ( arccot[x] - arctan[1/x] ) = 0 for all x not equal to 0.

B) Prove that there is no constant C such that arccot[x] - arctan[1/x] = C for all x not equal to 0. Explain why this does not contradict the zero-derivative theorem.

Any suggestions will be appreciated