`(cos 60^(@) xx cos 30^(@)+sin 60^(@)xx sin 30^(@))/(2 sin 30^(@) xx cos 0^(@)+ sin 90^(@))=?`

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

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^(@)

Evalutate : sin60^(@) cos 30^(@)+sin30^(@)cos 30^(@) .

The value of (cos 0^(@) + sin 45^(@) + sin 30^(@)) (sin 90^(@) - cos 45^(@) + cos 60^(@)) is

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^(@)

cos120^(@)=cos(90^(@)+30^(@)) =-sin30^(@)=-(1)/(2)

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

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

If cos 2x = cos 60^(@) cos 30^(@) + sin 60^(@) sin 30^(@), then the value of x is