[" (v) "sin90^(@)=2sin45^(@)*cos45^(@)],[" coc "60^(@)=2cos^(2)30^(@)-1=1-2sin^(2)30^(@)]

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^(@)

Evaluate sin^(2)45^(@)+cos^(2)60^(@)+cosec^(2)30^(@) .

Find the value of the following: (i) "sin"^(2)30^(@)+"sin"^(2)45^(@)+"sin"^(2)60^(@)+"sin"^(2)90^(@) (ii) 2"sin"^(2)30^(@)-3cos^(2)45^(@)+cos^(2)60^(@)

sin^(2) 60^(@) + 2 tan 45^(@) - cos^(2) 30^(@)

Prove that : 4(sin^(4)30^(@)+cos^(4)60^(@))-3(cos^(2)45^(@)-sin^(2)90^(@))=2

Prove that : 4(sin^(4)30^(@)+cos^(4)60^(@))-3(cos^(2)45^(@)-sin^(2)90^(@))=2

2tan ^ (2) 45 ^ (@) + cos ^ (2) 30 ^ (@) - sin ^ (2) 60 ^ (@)

The value of (1)/(2) sin ^(2) 90^(@) sin^(2) 30^(@) cos ^(2) 45^(@) + 4 tan ^(2) 30^(@) + (1)/(2) sin^(2) 90^(@) - 2 cos ^(2) 90^(@) is :

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^(@)

Calculate : (1-sin^(2)30^(@))/(1+sin^(2)30^(@))xx(cos^(2)60^(@)+cos^(2)30^(@))/("cosec"^(2)90^(@)-cot^(2)90^(@)) divide (sin60^(@) tan30^(@))