// 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
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