" (iv) "cos60^(@)=1-2sin^(2)30^(@)=2cos^(2)30^(@)-1

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^(@)

cos^(2)30^@-sin^(2)30^@=cos60^@

Prove that cos 60^(@)=cos^(2)30^(@)-sin^(2)30^(@) .

sin^(2)30+cos^(2)60

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^(@))

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^(@)

Evaluate : 3 cos^(2)60^(@)sec^(2)30^(@)-2 sin^(2)30^(@)tan^(2)60^(@)

Evaluate : ( 5 cos ^(2) 60^(@) + 4 sec ^(2) 30^(@) - tan ^(2) 45^(@))/( sin ^(2) 30^(@) + cos ^(2) 30^(@))

Prove that : cos^(2)30^(@)-sin^(2)30^(@)=cos60^(@)