Advertisements
Advertisements
प्रश्न
The value of sin 15° is:
पर्याय
`(sqrt3 + 1)/(2sqrt2)`
`(sqrt3 - 1)/(2sqrt2)`
`sqrt3/sqrt2`
`(sqrt3)/(2sqrt2)`
Advertisements
उत्तर
`(sqrt3 - 1)/(2sqrt2)`
Explanation:
sin 15° = sin(45° – 30°)
= sin 45° cos 30° – cos 45° sin 30°
`= 1/sqrt2 xx sqrt3/2 - 1/sqrt2 xx 1/2`
`=(sqrt3 - 1)/(2sqrt2)`
APPEARS IN
संबंधित प्रश्न
If cot α = `1/2`, sec β = `(-5)/3`, where π < α < `(3pi)/2 and pi/2` < β < π, find the value of tan(α + β). State the quadrant in which α + β terminates.
If A + B = 45°, prove that (1 + tan A) (1 + tan B) = 2 and hence deduce the value of tan 22`1/2`.
If sin A = `12/13`, find sin 3A.
If tan A – tan B = x and cot B – cot A = y prove that cot(A – B) = `1/x + 1/y`.
If tan α = `1/7`, sin β = `1/sqrt10`. Prove that α + 2β = `pi/4` where 0 < α < `pi/2` and 0 < β < `pi/2`.
Prove that cot 4x (sin 5x + sin 3x) = cot x(sin 5x - sin 3x).
If cos (α + β) = `4/5` and sin (α - β) = `5/13` where (α + β) and (α - β) are acute, then find tan 2α.
The value of sin (-420°)
The value of cos(-480°) is:
The value of 1 – 2 sin2 45° is:
