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Omni-MATH / For x∈(0,1) let y∈(0,1) be the number whose n-th digit after the decimal point is the 2^(n)-th digit after the decimal point of x. Show that if x is rational then so is y. [i]

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problem

For x∈(0,1) x \in (0, 1) let y∈(0,1) y \in (0, 1) be the number whose n n-th digit after the decimal point is the 2n 2^{n}-th digit after the decimal point of x x. Show that if x x is rational then so is y y. [i]
Plain-text mathematical notation (without MathML)
For x∈(0,1) let y∈(0,1) be the number whose n-th digit after the decimal point is the 2^(n)-th digit after the decimal point of x. Show that if x is rational then so is y.

[i]
Original LaTeX notation
For $ x \in (0, 1)$ let $ y \in (0, 1)$ be the number whose $ n$-th digit after the decimal point is the $ 2^{n}$-th digit after the decimal point of $ x$. Show that if $ x$ is rational then so is $ y$.

[i]

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