1. For any integer , there exists an integer k such that .
Write , where is an integer.
Now is divisible by but not .
And for all integer , , i is not divisible by . Therefore is even.
However, is odd since is divisible by . Therefore is also odd.
Hence , which is not an integer.
2. Simply make use of .
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Therefore do not worry about tomorrow, for tomorrow will worry about itself. Each day has enough trouble of its own.
