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

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

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

Find the value of (sin 50^(@))/(cos40^(@))+("cosec"40^(@))/(sec 50^(@))-4cos 50^(@) " cosec"40^(@).

Prove that: (sin70^@)/(cos20^@)+(cos e c\ 20^@)/(sec70^@)-2cos70^@\ cos e c\ 20^@=0

Solve (sin40^(@))/(cos50^(@))+(csc40^(@))/(sec50^(@))

Solve the following/ निम्नलिखित को हल कीजिए : (sin 40^@)/(cos 50^@)+ (cosec 50^@)/(sec 40^@)-4 cos50^@ cosec40^@

Evaluate : sin50^(@)cos40^(@)+cos40^(@)+cos50^(@)sin40^(@)

Evaluate : sin50^(@)cos40^(@)+cos40^(@)+cos50^(@)sin40^(@)

cos20^(0)cos40^(0)cos60^(0)cos80^(0) is equal to