Verified answer

(1/㏑5)*(㏑ctg(x^(1/4)))'=

(1/㏑5)*(1/ctg(x^(1/4))*(ctg(x^(1/4))'=

(1/㏑5)*(1/ctg(x^(1/4))*(-1/sin²(x^(1/4))(x^(1/4))'=

(1/㏑5)*(1/ctg(x^(1/4))*(-1/sin²(x^(1/4))(x^(-3/4))