What digit is immediately on the right of the decimal point in ?
Write (*) . Using the Binomial Theorem you can show that is an integer. (The terms with odd powers cancel each other, while those with even powers are integers.)
Let . As you've noted and therefore .
Rearranging (*) ,we have (^) , meaning that is the fractional part of .
Since , it must start like this . So , by (^).