// Calculate square-root of x define method newtons-sqrt (x) local method sqrt1 (guess) if (close? (guess)) guess else sqrt1 (improve (guess)) end if end sqrt1, method close? (guess) abs (guess * guess - x) < .0001 end close?, method improve (guess) (guess + (x / guess)) / 2 end improve; sqrt1 (1) end method newtons-sqrt |