SICP 問題1.40
(define (cubic a b c) (lambda (x) (+ (cube x) (* a (square x)) (* b x) c)))
gosh> (newtons-method (cubic 3 3 1) 1) -0.9999755158323895
(define (cubic a b c) (lambda (x) (+ (cube x) (* a (square x)) (* b x) c)))
gosh> (newtons-method (cubic 3 3 1) 1) -0.9999755158323895