(ii)quad cos^(2)13^(@)-sin^(2)77^(@)

Evalute (h) cos^(2)13^(@)-sin^(2)77^(@)

Evaluate : (i) cos^(2) 25^(@) - sin^(2)65^(@) - tan^(2)45^(@) (ii) ((sin 77)/(cos 13))^(2) + ((cos 77)/(sin 13))^(2) - 2 cos^(2) 45^(@)

The value of the determinant : |(sin^(2)13^(@)""sin^(2)77^(@)""tan135^(@)),(sin^(2)77^(@)""tan135^(@)""sin^(2)13^(@)),(tan135^(@)""sin^(2)13^(@)""sin^(2)77^(@))| is equal to :

|{:(sin^(2)13^(@),sin^(2)77^@,tan135^(@)),(sin^(2)77^(@), tan 135^(@),sin^(2)13^(@)),(tan135^(@),sin^(2)13^(@),sin^(2)77^(@)):}|=

Find the value of (a) sin(pi)/(10).sin(13pi)/(10) (b) cos^(2)48^(@)-sin^(2) 12^(@)

Find the value of (a) sin(pi)/(10)+sin(13pi)/(10) (b) cos^(2)48^(@)=sin^(2) 12^(@)

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

sin ^ (2) (13 ^ (@)), sin ^ (2) (77 ^ (@)), tan135 ^ (@) sin ^ (2) (77 ^ (@)), tan135 ^ (@), sin ^ (2) (13 ^ (@)) tan135 ^ (@), sin ^ (2) (13 ^ (@)), sin ^ (2) (77 ^ (@))]

Evaluate: ((sin 77^(@))/(cos 13^(@)))^(2)+((cos 77^(@))/(sin 13^(@)))^(2)-2cos^(2)45^(@)