हिंदी
तमिलनाडु बोर्ड ऑफ सेकेंडरी एज्युकेशनएचएससी विज्ञान कक्षा ११

Solve the following equations for which solution lies in the interval 0° ≤ θ < 360° cos 2x = 1 − 3 sin x

Advertisements
Advertisements

प्रश्न

Solve the following equations for which solution lies in the interval 0° ≤ θ < 360°

cos 2x = 1 − 3 sin x

योग
Advertisements

उत्तर

1 – 2 sin2x = 1 – 3 sinx

2 sin2 x – 3 sin x = 0

sin x(2 sin x – 3) = 0  

= sin x = 0 or 2 sin x – 3 = 0

sin x = 0 or sin x = `3/2`

sin x = `3/2` is not possible since sin x ≤ 1

∴ sin x = 0 = sin 0

The general solution is x = nit,

When n = 0, x = 0 ∉ (0°, 360°)

When n = 1, x = π ∈ (0°, 360°)

When n = 2, x = 2π ∉ (0°, 360°)

∴ The required solutions is x = π

shaalaa.com
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 3: Trigonometry - Exercise 3.8 [पृष्ठ १३३]

APPEARS IN

सामाचीर कलवी Mathematics - Volume 1 and 2 [English] Class 11 TN Board
अध्याय 3 Trigonometry
Exercise 3.8 | Q 2. (iv) | पृष्ठ १३३

संबंधित प्रश्न

Find the principal and general solutions of the equation  `cot x = -sqrt3`


If \[cosec x - \sin x = a^3 , \sec x - \cos x = b^3\], then prove that \[a^2 b^2 \left( a^2 + b^2 \right) = 1\]


Prove that: cos 24° + cos 55° + cos 125° + cos 204° + cos 300° = \[\frac{1}{2}\]


Prove that cos 570° sin 510° + sin (−330°) cos (−390°) = 0

Prove that: \[\tan\frac{11\pi}{3} - 2\sin\frac{4\pi}{6} - \frac{3}{4} {cosec}^2 \frac{\pi}{4} + 4 \cos^2 \frac{17\pi}{6} = \frac{3 - 4\sqrt{3}}{2}\]

 


Prove that

\[\left\{ 1 + \cot x - \sec\left( \frac{\pi}{2} + x \right) \right\}\left\{ 1 + \cot x + \sec\left( \frac{\pi}{2} + x \right) \right\} = 2\cot x\]

 


Prove that

\[\frac{\tan (90^\circ - x) \sec(180^\circ - x) \sin( - x)}{\sin(180^\circ + x) \cot(360^\circ - x) cosec(90^\circ - x)} = 1\]

 


If \[cosec x - \cot x = \frac{1}{2}, 0 < x < \frac{\pi}{2},\]

 

If \[cosec x + \cot x = \frac{11}{2}\], then tan x =

 


\[\sec^2 x = \frac{4xy}{(x + y )^2}\] is true if and only if

 


If x is an acute angle and \[\tan x = \frac{1}{\sqrt{7}}\], then the value of \[\frac{{cosec}^2 x - \sec^2 x}{{cosec}^2 x + \sec^2 x}\] is


sin2 π/18 + sin2 π/9 + sin2 7π/18 + sin2 4π/9 =


Solve the following equation:

\[2 \sin^2 x + \sqrt{3} \cos x + 1 = 0\]

Solve the following equation:

\[\cos x \cos 2x \cos 3x = \frac{1}{4}\]

Solve the following equation:

\[\sin x + \sin 2x + \sin 3 = 0\]

Solve the following equation:
\[\sec x\cos5x + 1 = 0, 0 < x < \frac{\pi}{2}\]


If cos x = k has exactly one solution in [0, 2π], then write the values(s) of k.

 

If a is any real number, the number of roots of \[\cot x - \tan x = a\] in the first quadrant is (are).


Choose the correct alternative:
`(cos 6x + 6 cos 4x + 15cos x + 10)/(cos 5x + 5cs 3x + 10 cos x)` is equal to


Solve `sqrt(3)` cos θ + sin θ = `sqrt(2)`


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×