" 16.The value of "cos ec10^(@)+cos ec50^(@)-cos ec70^(@)=

Find the exact value of cos ec10^(@)+cos ec50^(@)-cos ec70^(@)

Find the exact value of cos ec10^(@)+cos ec50^(@)-cos ec70^(@)

cos ec31 ^ (@) - sec59 ^ (@)

cos ec15 ^ (@) + sec15 ^ (@)

cos ec15 ^ (@) + sec15 ^ (@) =

cos48^(@)cos23^(@)cos ec42^(@)cos ec67^(@)=1

cos ec10 ^ (@) - sqrt (3) sec10 ^ (@) =

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

cos ec15^(@)+sec15^(@) is equal to