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#lang racket
(require sicp)
(define (fixed-point damper f first-guess)
(define (close-enough? v1 v2)
(< (abs (- v1 v2)) 0.0001))
(define (try guess)
(let ((next (damper guess (f guess))))
(newline)
(display next)
(if (close-enough? guess next)
next
(try next))))
(try first-guess))
(define (golden-ratio)
(fixed-point
(lambda (x) (+ 1 (/ 1 x)))
1.0))
(define (log1000)
(fixed-point
(lambda (guess next)
next)
(lambda (x) (/ (log 1000) (log x)))
2.0))
(define (log1000-average-damped)
(define (average a b)
(/ (+ a b) 2))
(fixed-point
(lambda (guess next)
(average guess next))
(lambda (x) (/ (log 1000) (log x)))
2.0))
(log1000)
(println " *** second time")
(log1000-average-damped)
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