Advertisements
Advertisements
प्रश्न
Express each one of the following in terms of trigonometric ratios of angles lying between 0° and 45°
cot 85° + cos 75°
उत्तर
We know that `cot (90^@ - theta) = tan theta` and `cos (90^@ - theta) = sin theta` so
`cot 85° + cos 75° = cot(90^@ - 5^@) + cos(90^@ - 15^@)`
`= tan 5^@ +sin 15^@`
Thus the desired expression is `tan 56^@ + sin 15^@`
APPEARS IN
संबंधित प्रश्न
If tan (A + B) = `sqrt3` and tan (A – B) = `1/sqrt3`; 0° < A + B ≤ 90°; A > B, find A and B.
State whether the following is true or false. Justify your answer.
The value of sinθ increases as θ increases.
If A, B, C are the interior angles of a triangle ABC, prove that
`tan ((C+A)/2) = cot B/2`
Prove the following :
`(cos(90°−A) sin(90°−A))/tan(90°−A) - sin^2 A = 0`
Evaluate: `cos 58^@/sin 32^@ + sin 22^@/cos 68^@ - (cos 38^@ cosec 52^@)/(tan 18^@ tan 35^@ tan 60^@ tan 72^@ tan 65^@)`
Without using trigonometric tables, prove that:
cos54° cos36° − sin54° sin36° = 0
Prove that:
cos 30° . cos 60° - sin 30° . sin 60° = 0
If A = 30o, then prove that :
2 cos2 A - 1 = 1 - 2 sin2A
Without using tables, find the value of the following: `(sin30°)/(sin45°) + (tan45°)/(sec60°) - (sin60°)/(cot45°) - (cos30°)/(sin90°)`
Find the value of x in the following: 2 sin3x = `sqrt(3)`
