$\"\"$

The functions are $\"\"$ and $\"\"$ .

Graph:

Graph the functions $\"\"$ and $\"\"$ :

$\"\"$

Observe the graph:

The both functions are equal for all real numbers.

$\"\"$

$\"\"$ and $\"\"$ .

Consider the function $\"\"$ .

Trigonometry reciprocal identity: $\"\"$ .

$\"\"$

Hence $\"\"$ .

$\"\"$

The both functions are equal for all real numbers.