`(cos 28^(@))/(sin 62^(@))=?`

Consider the following : 1. (cos 75^(@))/(sin 15^(@)) + (sin 12^(@))/(cos 78^(@)) - (cos 18^(@))/(sin 72^(@)) =1 2. (cos 35^(@))/(sin 55^(@)) - (sin 11^(@))/(9cos 79^(@)) + cos 28^(@) "cosec" 62^(@) =1 3. (sin 80^(@))/(cos 10^(@)) - sin 59^(@).sec 31^(@) =0 Which of the above are correct ?

Evaluate 2(cos^(2)28^(@)-sin^(2)62^(@)) .

(1+cos56^(@)+cos58^(@)-cos66^(@))/(cos28^(@)cos29^(@)sin33^(@))=

cos56^(@)+cos58^(@)-cos66^(@)-4cos28^(@)cos29^(@)sin33^(@)=

(1-(cos61^(@))/(cos1^(@)))(1-(cos62^(@))/(cos2^(@)))(1-(cos63^(@))/(cos3^(@)))...(1-(cos119^(@))/(cos59^(@)))

Find the value of cos28^(@).cos32^(@)-sin28^(@).sin32^(@) :

If cos56^(0)+cos58^(0)-cos66^(0)-4cos28^(0)-cos29^(@)sin33^(@)=lambda then |2 lambda|=

Prove that ((sin^(2)73^(@)+sin^(2)17^(@)))/((cos^(2)28^(@)+cos^(2)62^(@)))=1.

If 1+cos56^(0)+cos58^(0)-cos66^(0)=k cos28^(0)cos29^(@)sin33^(@) then the value of k is

Prove that : (sin A+cos A)/(sin A-cos A)+(sin A-cos A)/(sin A+cos A)=(2)/(sin^(2)-cos^(2)A)