`cos 5^(@) - sin 25^(@) ` is equal to

sin ^(2) 25^(@) + sin ^(2) 65^(@) is equal to

cos5^@-sin25^@ is equal to

sin^(2)5^(@) + sin^(2)25^(@) + sin^(2)45^(@) + sin^(2) 65^(@) + sin^(2) 85^(@) is equal to:

The smallest positive value of x (in degrees) for whichcos tanx=(cos5^@ cos 20^@ + cos 35^@ cos 50^@-sin 50^@ sin 20^@ - sin35^@ sin50^@)/(sin5^@ cos 20^@ - sin 35^@ cos 50^@ + cos 5^@ sin 20^@ - cos 35^@ sin 50^@) is equal to

The smallest positive value of x (in degrees) for whichcos tanx=(cos5^@ cos 20^@ + cos 35^@ cos 50^@-sin 50^@ sin 20^@ - sin35^@ sin50^@)/(sin5^@ cos 20^@ - sin 35^@ cos 50^@ + cos 5^@ sin 20^@ - cos 35^@ sin 50^@) is equal to

The value of (cos ^(6)5^(@)-15 cos ^(4) 5^(@) sin ^(2)5^(@)+15 cos ^(2)5^(@)sin ^(4) 5^(@)-sin ^(6)5^(@)) is equal to-

cos^(2)(97.5^(@))-sin^(2)(37.5^(@)) is equal to-

If cos 25^(@) + sin 25^(@) =p , then: cos 50^(@)=