Prove that:`cos 570^0s in 510^0+sin(-330^0)cos(-390^0)=0`

Prove that: cos 570^0sin 510^0+sin(-330^0)cos(-390^0)=0

Prove that: cos570^(@)s in510^(0)+sin(-330^(@))cos(-390^(@))=0

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

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

Prove that: cos420^@ sin390^@+ sin(-300^@)cos(-330^@)=1

Prove that: \ sin 50^0+sin 10^0=cos 20^0

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

Prove that: sin 80^0-cos 70^0=cos 50^0