The value of the expression `(tan^2 20^0-sin^2 20^0)/((tan^2 20^0)(sin^2 20^0))` is__________

Explanation

`(tan^2 20^@-sin^2 20^@)/(tan^2 20^@ sin^2 20^@)`

`=1/sin^2 20^@ - 1/tan^2 20^@`

`=cosec^2 20^@ - cot^2 20^@`

`=1`

As, `1` is not a surd and a prime number, we can reject option `b` and `c`.

Also, `1` is integer and not a composite number.

So, optiopn `d` is the correct option.