" 25."sin42^(@)*cos48^(@)+cos42^(@)*sin48^(@)=1

sin42^(@)sec48^(@)+cos42^(@)cos ec48^(@)=2

Evaluate: sin 42^(@)sin 48^(@)-cos 42^(@)cos 48^(@)

Show that: sin 42^(@)sec 48^(@)+cos 42^(@)cosec 48^(@)=2

Evaluate : (i) (cos 55^(@))/(sin 35^(@)) + (cot 35^(@))/(tan 55^(@)) (ii) sin 42^(@) sin 48^(@) - cos 42^(@) cos 48^(@)

sin48^(@)sec42^(@)+cos48^(@)csc42^(@)=

(sin48^(@))/(cos42^(@))+(cos48^(@))/(sin42^(@))=2

Prove that : (i) sin42^(@)cos48^(@)+sin48^(@)cos42^(@)=1 (ii) cos70^(@)cos20^(@)-sin70^(@)sin20^(@)=0

Prove that : (i) sin42^(@)cos48^(@)+sin48^(@)cos42^(@)=1 (ii) cos70^(@)cos20^(@)-sin70^(@)sin20^(@)=0

Prove that sin 12^(@) sin18^(@)sin42^(@) sin48^(@) sin 72^(@) sin78^(@)=(cos18^(@))/(32) .

Prove that sin 12^(@) sin18^(@)sin42^(@) sin48^(@) sin 72^(@) sin78^(@)=(cos18^(@))/(32) .