Without using trigonometric tables, evaluate each of the following: `(cos^2 20^0+cos^2 70^0)/(sec^2 50^0-cot^2 40^0)+2cosec^2 58^0-2cot58^0tan32^0-` `4tan13^0tan37^0tan45^0tan53^0tan77^0`

Explanation

`(cos^2 20^o +cos^2 70^o)/(sec^2 50^o-cot^2 40^o)+2cosec ^2 58^o - 2 cot 58^o tan32^o-4 tan 13^o tan 376o tan 45^o tan 53^otan 77^o`


`(cos^2 20^o +sin ^2 20^o)/(sec^2 50^0-tan^2 50 ^o)+2 cosec^2 58^o-2cot58^0cot58^o-4tan13^ocot13^ocot53^o tan53^o tan45^o`


`1/1+2 cosec^2 58^o-2 cot 58^0 cot58^0-4X1X1X1X1`


`1+2(cosec^2 58^o-cot^2 58^o)-4`


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