cos510^(@)cos330^(@)+sin390^(@)cos120^(@)=

Prove that: cos510^(0)cos330^(@)+s in390^(@)cos120^(@)=-1

cos 510^@cos330^@+sin 390^@cos120^@ =

Evaluate the following: i) cos120^(@)sin390^(@)+cos330^(@)cos150^(@) ii) sin^(2)(3pi)/(4)+cos^(2)pi/4+sec^(2)pi/3

Evaluate the following: i) cos120^(@)sin390^(@)+cos330^(@)cos150^(@) ii) sin^(2)(3pi)/(4)+cos^(2)pi/4+sec^(2)pi/3

Prove that: cos510^0cos 330^0+sin 390^0cos 120^0=-1.

sin 420^(@) * cos 390^(@)- cos(-330^(@))* sin(-300^(@))=

Prove that: (a) cos510^(@) sin510^(@) + sin(-330^(@)) cos(-390^(@))=0 b) tan(11pi)/(3) -2sin(9pi)/3-3/4"cosec"^(2)pi/4 + 4cos^(2)(17pi)/6=(3-2sqrt(3))/2

Prove that: (a) cos510^(@) sin510^(@) + sin(-330^(@)) cos(-390^(@))=0 b) tan(11pi)/(3) -2sin(9pi)/3-3/4"cosec"^(2)pi/4 + 4cos^(2)(17pi)/6=(3-2sqrt(3))/2

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

Prove that sin750^(@)cos480^(@)+cos120^(@)cos60^(@)=(-1)/2