$\"\"$

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

The quotient identity : $\"\"$ .

Substitute $\"\"$ and $\"\"$ in above identity. \ \

$\"\"$

$\"\"$ .

$\"\"$

The reciprocal identities : $\"\"$

$\"\"$

$\"\"$ .

$\"\"$ ,

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

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