Question

calcule a derivada de y = ln c
                                      x

Answer 1

$y=\frac{\ln c}{x}\\\\y'=\frac{(\ln c)'\cdot x-\ln c \cdotx'}{x^2}\\\\y'=\frac{0\cdot x-\ln c \cdot1}{x^2}\\\\\boxed{y'=-\frac{\ln c}{x^2}}$