Evaluate the following: `s in 78^0cos 18^0-cos 78^0s in 18^0`

Evaluate the following: sin 78^0cos 18^0-cos 78^0sin 18^0

Evaluate the following: cos 47^0cos 13^0-sin 47^0 sin 13^0

Evaluate the following: sin 36^0cos9^0+cos36^0 sin9^0

Evaluate the following: cos 80^0cos 20^0+ sin 80^0 sin 20^0

Evaluate the following: (i) sin39^0-cos51^0 (ii) cos e c25^0-sec65^0 +cot34^0-tan56^0 (iii) (sin36^0)/(cos54^0)-(sin54^0)/(cos36^0) +cos^2 13^0-sin^2 77^0

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

Without using trigonometric tables, evaluate the following: (sec37^0)/(cos e c53^0)+2cot15^0cot25^0cot45^0cot75^0cot65^0(sin^2 18^0+sin^2 72^0)

Evaluate the following: (i) cos e c\ 31^@-sec59^@ (ii) (sin72^@+cos18^@)(sin72^@-cos18^@)

Evaluate the following: (cos37^0)/(sin53^0) (ii) (tan54^0)/(cot36^0) (iv) (cos e c34^0)/(sec56^0)

Evaluate: 18 times 0