`(i) cos 15^@ (ii) cos75^@ (iii) tan15^@ (iv)tan75^@`

Evaluate: i) cos75^(@) , ii) cos15^(@) , iii) tan75^(@) , iv) tan105^(@) , v) sin105^(@)

Calculate the value of (i) sin 15^(@) " "(ii) cos 15^(@)" "(iii) tan 15^(@) (iv) sin 75^(@) " "(v) cos 75^(@) " "(vi) tan 75^(@)

cos15^(@)-cos75^(@)=

Find the values of the following: sin75^0 (ii) cos75^0 (iii) sin15^0 (iv) cos15^0

Without using the trigonometric tables, evaluate the following : (11)/(7) (sin 70^(@))/(cos 20^(@)) - (4)/(7) (cos 53^(@) "cosec" 37^(@))/(tan 15^(@) tan 35^(@) tan 55^(@) tan 75^(@))

finding trigonometric ratios of angles which are multiple of 15 (i) cos15 (ii) sin15 (ii) tan 15 (using formula A-B)::

tan75^(@)+cot75^(@)=

Without using trigonometric tables , evaluate : (i) (sin11^(@))/(cos79^(@)) (ii) (sec15^(@))/("cosec"75^(@)) (iii) (tan54^(@))/(cot36^(@)) (iv) (cos68^(@))/(sin22^(@)) (v) ("cosec"24^(@))/(sec66^(@)) (vi) (cot18^(@))/(tan72^(@))

Which of the following number(s) is/are rational? (A) sin15^(@) (B) cos15^(@) (C) sin15^(@)cos15^(@)(D)sin15^(@)cos75^(@)

Which of the following number (s) is/are rational number? (A) sin15^(@) (B) cos15^(@) (C) sin15^(@)cos15^(@)(D)sin15^(@)cos75^(@)