Question

If f is a real valued function of complex variable then f has derivative or derivative vanish.​

Answer 1

Answer:

Cauchy-Riemann equations give the conditions that for which complex functions are differentiable in a complex mathematical space.

each real-valued function could be imagined as a complex function of imaginary part equal to zero, so the same conditions should be satisfied for them too; but it seems that these equations have no sense according to real-valued function.

the question is that should these conditions be satisfied for real-valued functions? if yes, how? ; if