" (ix) "cos60^(@)*cos30^(@)-sin60^(@)*sin30^(@)=cos90^(@)

Show that (i) cos60^(@)*cos30^(@)-sin60^(@)*sin30^(@)=cos90^(@) (ii) cos60^(@)=1-2sin^(2)30^(@)=2cos^(2)30^(@)-1 (iii) (tan60^(@)-tan30^(@))/(1+tan60^(@)*tan30^(@))=tan30^(@)

Verify each of the following : (i) sin60^(@)cos30^(@)-cos60^(@)sin30^(@)=sin30^(@) (ii) cos60^(@)cos30^(@)+sin60^(@)sin30^(@)=cos30^(@) (iii) 2sin 30^(@)cos30^(@)=sin60^(@) (iv) 2sin45^(@)cos45^(@)=sin90^(@)

sin60^(@).cos30^(@)+cos30^(@)*sin60^(@)

Evaluate : cos60^(@)cos30^(@)+ sin 60^(@)sin30^(@)

Evaluate each of the following : cos60^(@)cos30^(@)-sin60^(@)sin30^(@)

"(1) "sin60^(@)cos30^(@)+sin30^(@)cos60^(@)

Evaluate : (i) sin60^(@)*cos30^(@)-cos60^(@)*sin30^(@) (ii) tan30^(@)*cosec60^(@)+tan60^(@)*sec30^(@) .

Find the value of cos60^(@) cos 30^(@)-sin 60^(@) sin 30^(@)

Show that : (i) (1-sin60^(@))/(cos60^(@))=(tan60^(@)-1)/(tan60^(@)+1) (ii) (cos30^(@)+sin60^(@))/(1+sin30^(@)+cos60^(@))=cos30^(@)

Is it right to say that cos ( 60^(@) + 30 ^(@) ) = cos 60^(@) cos 30 ^(@) -sin 60^(@) sin 30 ^(@)