This is my Clojure solution to Chapter 1, Exercise 39:
(ns sicp.ch1.ex39
(:require [sicp.ch1.ex16 :as ch1-ex16]
[sicp.ch1.ex37 :as ch1-ex37]))
(defn tan-cf
[x k]
(/
(ch1-ex37/cont-frac (constantly (- (ch1-ex16/square x)))
#(inc (* 2 (dec %)))
k)
(- x)))
(comment
(double (tan-cf (/ Math/PI 6) 10)) ; => 0.5773502691896257
#__)
