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

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 : ( (3cos55^0) / (7sin35^0))-(4/7)(cos70^0cos e c20^0)/(tan5^0tan25^0tan45^0tan65^0tan85^0

Evaluate : tan35^0tan40^0tan45^0tan50^0tan55^0

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

Evaluate the following: cos 47^0cos 13^0-sin 47^0 sin 13^0

Evaluate the following: cos 80^0cos 20^0+ sin 80^0 sin 20^0

Prove that: t a n 20^0tan40^0tan60^0tan80^0=3

Evaluate the following: sin 78^0cos 18^0-cos 78^0sin 18^0

Prove that tan20^0tan40^0tan80^0=tan60^0

Prove that: tan20^0tan40^0tan80^0=tan60^0