`(cos3 0^(@)-sin2 0^(@))/(cos4 0^(@)+cos2 0^(@))=4/(sqrt(3))cos4 0^(@)cos8 0^(@)`

Evaluate (2cos4 0^(@)-cos2 0^(@))/(sin2 0^(@)

Prove that cos 2 0^(@)cos4 0^(@)cos6 0^(@)cos8 0^(@)=1/16

cos4 0^(@)+cos2 0^(@))=3(cos1 0^(@)+sin2 0^(@)) 40 CUSOUcos 40^@ + cos 20O 4(cos310^@ + sin320^@) = 3(cos 10^@ + sin20^@)N3.1 = 4

4(sin24^(0)+cos6^(@))=sqrt(3)+sqrt(15)

Let x=sin1^(0), then the value of the expression.(1)/(cos0^(0)cos1^(0))+(1)/(cos1^(0)cos2^(0))+(1)/(cos2^(0)cos3)+(1)/(cos44^(0)cos45^(@)) is equal to (a) x (b) (1)/(x) (c) (sqrt(2))/(x) (d) (x)/(sqrt(2))

Show that sin70^(0)cos10^(0)-cos70^(0)sin10^(0)=(sqrt(3))/(2)

Prove that: (cos30^0+sin60^0)/(1+cos60^0+sin30^0)=(sqrt(3))/2

cos1^(0)+cos2^(0)+cos3^(0)+ . . .+cos180^(0) =

4\ cos\ 20^0\ -sqrt(3)\ cot\ 20^0\ =