Chapter 1, Building Abstractions with Procedures

Section - Formulating Abstractions with Higher-Order Procedures

Exercise 1.39


Procedure:

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(define (tan-cf x n)
    (let ((num-const (* -1 x x)))
      (define (num k) (if (= k 1) x num-const))
      (define (den k) (- (* 2 k) 1))
      (cont-frac-itr num den n)
    )        
)

Sample output:

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(define pi (/ 22.0 7))

> (tan-cf (/ pi 4) 10)
; 1.0006324445845896

> (tan-cf 0 10)
; 0