Here is some nice function I've made that calculates a square root of a number:

k=>(f=>f(f))(f=>x=>x==(y=(x+k/x)/2)?x:f(f)(y))(1)

At first look this function is completely cryptic, however it produces exactly the same results for positive numbers as Math.sqrt() function. Let's take a closer look and find out how does it work.

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