Evaluate `(2cos 40^0-cos 20^0)/(sin 20^0)=`

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

Prove that : (cos 20^0 - sin 20^0)/(cos 20^0 + sin 20^0) = tan 25^0

Evaluate : 4(sin^4 30^0+cos^4 60^0)-2/3(sin^2 60^0-cos^2 45^0)+1/2tan^2 60^0

Evaluate : (sin50^0)/(cos40^0)+(cos e c40^0)/(sec50^0)-4cos50^0cos e c40^0

Evaluate each of the following: (a) cos(40^0-theta)-sin(50^0+theta)+(cos^2 40^0+cos^2 50^0)/(sin^2 40^0+sin^2 50^0) (b) (cos70^0)/(sin20^0)+(cos55^0cos e c35^0)/(tan5^0tan25^0tan45^0tan65^0tan85^0) (c) 2((cos58^0)/(sin32^0))-sqrt(3)((cos38^0cos e c52^0)/(tan15^0tan60^0t a n75^0))

Evaluate : (cos 70^(@))/(sin 20^(@))+(cos 59^(@))/(sin31^(@))-8sin^(2)30^(@)

Evaluate : (cos 70^(@))/(sin 20^(@))+(cos 59^(@))/(sin31^(@))-8sin^(2)30^(@)

Value of "cot"40^0dotcot 20^0(4sin 10^0-1) is -1 (b)1 (c) 2 (d) 0

Prove that: cos 100^0+cos 20^0=cos 40^0

Prove that : cos 20^0cos 40^0cos 60^0cos 80^0=1/(16)