(b * c * (d - 1) * (x / a) ^ (b - 1) * exp((x / a) ^ b + a * c * (1 - exp((x / a) ^ b))))/((1-(1-d)*exp(a*c*(1-exp(x/a)^(b))))*(log(d))) c * b * d * (x / a) ^ (b - 1 ...