Advertisements
Advertisements
प्रश्न
Find the value of:
sin 15°
उत्तर
sin 15°
= sin (45° – 30°)
= sin 45° cos 30° – cos 45° sin 30°
= `(1/sqrt(2))(sqrt(3)/2) - (1/sqrt(2))(1/2)`
= `(sqrt(3) - 1)/(2sqrt(2)`
Notes
Answer given in the textbook is `(sqrt(3) + 1)/(2sqrt(2)`. However, as per our calculation it is `(sqrt(3) - 1)/(2sqrt(2)`.
APPEARS IN
संबंधित प्रश्न
Find the values of:
cos 75°
Find the values of:
tan 105°
Find the values of:
cot 225°
Find the value of :
sin (495°)
Find the value of :
cos (600°)
Find the value of :
tan (– 690°)
Prove the following:
sec 840° . cot (– 945°) + sin 600° tan (– 690°) = `3/2`
Prove the following:
`("cosec"(90^circ - x)sin(180^circ - x)cot(360^circ - x))/(sec(180^circ + x)tan(90^circ + x)sin(-x))` = 1
Prove the following:
cosθ + sin (270° + θ) − sin (270° − θ) + cos (180° + θ) = 0
Prove the following:
sin 20° sin 40° sin 80° = `sqrt(3)/8`
Prove the following:
sin 18° = `(sqrt(5) - 1)/4`
Prove the following:
cos 36° = `(sqrt(5) + 1)/4`
Prove the following:
sin 36° = `(sqrt(10 - 2sqrt(5)))/4`
Prove the following:
sin47° + sin61° − sin11° − sin25° = cos7°
If a = sin 175°+ cos 175°, then ______.
The value of sin 495° is ______.
The value of sin(– 1125°) is ______.
The value of `sin((25π)/3)` is ______.
The value of `cos((41π)/4)` is ______.
The value of `2 cot^2(π/6) + 4 tan^2(π/6) - 3 "cosec"(π/6)` is ______.
Find the value of `cos ((29 π)/3)`.
If `cosA/3 = cosB/4 = 1/5, - π/2 < A < 0` and `- π/2 < B < 0`, then the value of 2 sin A + 4 sin B is ______.
The value of cos 480° sin 150° + sin 600° cos 390° is ______.
The value of `cos^2 π/16 + cos^2 (3π)/16 + cos^2 (5π)/16 + cos^2 (7π)/16` is ______.
sin2 17.5° + sin2 72.5° is equal to ______.
cos 1° + cos 2° + cos 3° + ... + cos 180° is equal to ______.
In a ΔABC, if ∠A = `π/2`, then cos2 B + cos2 C is equal to ______.
If ΔABC is a right angled at C, then tan A + tan B is equal to ______.
If `sin A - sqrt(6) cos A = sqrt(7) cos A`, then `cos A + sqrt(6) sin A` is equal to ______.
The value of the expression sin6 θ + cos6 θ + 3 sin2 θ . cos2 θ is ______.
The value of cos(– 870°) is ______.
cos 1°. cos 2°. cos 3° ...... cos 179° = ______.
