$\"\"$

\

The real number is $\"\"$ .

\

At $\"\"$ ,

\

$\"\"$ (Since $\"\"$ ) $\"\"$ .

\

$\"\"$ (Since $\"\"$ ) $\"\"$ .

\

$\"\"$ .

\

$\"\"$

\

The values of $\"\"$ , $\"\"$ , and $\"\"$ .