Answer
$$\left( {2,\frac{\pi }{3},4} \right)$$
Work Step by Step
$$\eqalign{
& \left( {1,\sqrt 3 ,4} \right) \cr
& \left( {x,y,z} \right):{\text{ }}\left( {1,\sqrt 3 ,4} \right) \to x = 1,{\text{ }}y = \sqrt 3 ,{\text{ }}z = 4 \cr
& {\text{Rectangular to cylindrical}} \cr
& {r^2} = {x^2} + {y^2} \to r = \sqrt {{{\left( 1 \right)}^2} + {{\left( {\sqrt 3 } \right)}^2}} = 2 \cr
& \tan \theta = \frac{y}{x} \to \theta = {\tan ^{ - 1}}\left( {\frac{{\sqrt 3 }}{1}} \right) = \frac{\pi }{3} \cr
& z = z \to z = 4 \cr
& {\text{The cylindrical coordinates are:}} \cr
& \left( {2,\frac{\pi }{3},4} \right) \cr} $$
