Without using trigonometric tables. Find the value of `cos70/sin20+cos57*cosec33-2 cos60`

Without using trigonometric tables,find the value of ((sin50^(@))/(cos40^(@)))+((cos ec40^(@))/(sec50^(@)))-4cos50^(@)cos ec40^(@)

Without using trigonometric tables, find the value of : (2)/(3) ((sec 56^(@))/( cosec 34^(@))) - 2 cos^(2) 20^(@) + (1)/(2) cot 28^(@) cot 35^(@) cot 45^(@) cot 62^(@) cot 55^(@) - 2 cos ^(2) 70^(@)

Without using trigonometric tables, show that (cos 70^(@))/( sin 20^(@)) + cos 49^(@) cosec41^(@) = 2

Without using trigonometric tables, prove that sec70^(@)sin 20^(@) + cos 20^(@) cosec 70^(@)=2 .

Without using trigonometric tables, evaluate : (i) cos 48^@-sin42^@ (ii) cosec31^@-sec59^@ (iii) cot 34^@-tan56^@ (iv) cos^2 13^@-sin^2 77^@

Without using Trigonometric Tables evaluate the following :- sec70^@sin20^@-cos20^@cosec70^@ .

Without using Trigonometric tables, evaluate:- (cos^2 20^@+cos^2 70^@)/(sin^2 59^@+sin^2 31^@) .

The value of sec70^@sin20^@+cos20^@cosec70^@ is

Without using trigonometric tables, evaluate each of the following: (sec^2 54^0-cot^2 36^0)/(cos e c^2 57^0-tan^2 33^0)+2sin^2 38^0sec^2 52^0-sin^2 45^0

Without using Trigonometric Tables evaluate the following :- (sec50^@sin40^@+cos40^@cosec50^@)