`sin1770^@.cos510^@+cos290^@.tan470^@`

(cos9^(@)+sin9^(@))/(cos9^(@)-sin9^(@))=tan54^(@)

(cos20^(@)-sin20^(@))/(cos20^(@)+sin20^(@))=tan25^(@)

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

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

Prove that cos510^@cos330^@+sin390^@cos120^@=-1

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

Show that cos510^@cos330^@-sin390^@cos120^@=-1/2

Prove that, cos510^(@)cos330^(@)+sin390^(@)cos120^(@)=-1 .

If cos theta=-(1)/(2) and piltthetalt(3pi)/(2) , then find the value of 4 tan^(2)theta-3cos ec^(2)theta . Prove that, cos 570^(@) sin510^(@)+sin(-330^(@))cos(-390^(@))=0