y'=1/[2√(x+√(x+√x))]*(x+√(x+√x))'=1/[2√(x+√(x+√x))]*[1+1/(2√(x+√x))]*(x+√x)'=1/[2√(x+√(x+√x))]*[1+1/(2√(x+√x))]*[1+1/(2√x)]
