Home
Class 12
MATHS
If sin(x +3alpha)=3 sin (alpha-x), then...

If `sin(x +3alpha)=3 sin (alpha-x)`, then

A

`tan x = tan alpha`

B

`tan x = tan^(2)alpha`

C

`tan x = tan^(3)alpha`

D

`tan x=3 tan alpha`

Text Solution

AI Generated Solution

The correct Answer is:
To solve the equation \( \sin(x + 3\alpha) = 3 \sin(\alpha - x) \), we will use trigonometric identities and algebraic manipulation. Here is the step-by-step solution: ### Step 1: Apply the Sine Addition Formula We start with the left side of the equation and apply the sine addition formula: \[ \sin(x + 3\alpha) = \sin x \cos(3\alpha) + \cos x \sin(3\alpha) \] Thus, we rewrite the equation as: \[ \sin x \cos(3\alpha) + \cos x \sin(3\alpha) = 3 \sin(\alpha - x) \] ### Step 2: Apply the Sine Subtraction Formula Now, we apply the sine subtraction formula on the right side: \[ \sin(\alpha - x) = \sin \alpha \cos x - \cos \alpha \sin x \] So, we can rewrite the equation as: \[ \sin x \cos(3\alpha) + \cos x \sin(3\alpha) = 3(\sin \alpha \cos x - \cos \alpha \sin x) \] ### Step 3: Rearranging the Equation Rearranging gives us: \[ \sin x \cos(3\alpha) + \cos x \sin(3\alpha) = 3 \sin \alpha \cos x - 3 \cos \alpha \sin x \] This can be rearranged to: \[ \sin x \cos(3\alpha) + 3 \cos \alpha \sin x = 3 \sin \alpha \cos x - \cos x \sin(3\alpha) \] ### Step 4: Grouping Terms Now, we can group the terms involving \(\sin x\) and \(\cos x\): \[ \sin x (\cos(3\alpha) + 3 \cos \alpha) = \cos x (3 \sin \alpha - \sin(3\alpha)) \] ### Step 5: Factor Out Common Terms We can factor out \(\sin x\) and \(\cos x\): \[ \frac{\sin x}{\cos x} = \frac{3 \sin \alpha - \sin(3\alpha)}{\cos(3\alpha) + 3 \cos \alpha} \] This simplifies to: \[ \tan x = \frac{3 \sin \alpha - \sin(3\alpha)}{\cos(3\alpha) + 3 \cos \alpha} \] ### Step 6: Use the Sine and Cosine Triple Angle Formulas Using the triple angle formulas: \[ \sin(3\alpha) = 3 \sin \alpha - 4 \sin^3 \alpha \] \[ \cos(3\alpha) = 4 \cos^3 \alpha - 3 \cos \alpha \] Substituting these into the equation gives: \[ \tan x = \frac{3 \sin \alpha - (3 \sin \alpha - 4 \sin^3 \alpha)}{(4 \cos^3 \alpha - 3 \cos \alpha) + 3 \cos \alpha} \] This simplifies to: \[ \tan x = \frac{4 \sin^3 \alpha}{4 \cos^3 \alpha} \] Thus: \[ \tan x = \tan^3 \alpha \] ### Step 7: Final Result From this, we conclude: \[ \tan x = \tan^3 \alpha \] This implies: \[ \tan x = \tan^3 \alpha \implies 10 x = 10^3 \alpha \] ### Conclusion Thus, the final answer is: \[ 10 x = 10^3 \alpha \]

To solve the equation \( \sin(x + 3\alpha) = 3 \sin(\alpha - x) \), we will use trigonometric identities and algebraic manipulation. Here is the step-by-step solution: ### Step 1: Apply the Sine Addition Formula We start with the left side of the equation and apply the sine addition formula: \[ \sin(x + 3\alpha) = \sin x \cos(3\alpha) + \cos x \sin(3\alpha) \] Thus, we rewrite the equation as: ...
Promotional Banner

Topper's Solved these Questions

  • TRIGONOMETRIC RATIOS FOR COMPOUND, MULTIPLE, SUB-MULTIPLE ANGLES, AND TRANSFORMATION FORMULAS

    CENGAGE ENGLISH|Exercise Multiple Correct Answers Type|6 Videos
  • TRIGONOMETRIC RATIOS AND TRANSFORMATION FORMULAS

    CENGAGE ENGLISH|Exercise Matrix Match Type|1 Videos
  • VECTOR ALGEBRA

    CENGAGE ENGLISH|Exercise All Questions|532 Videos

Similar Questions

Explore conceptually related problems

If sin 3 alpha =4 sin alpha sin (x+alpha ) sin(x-alpha ) , then

If y = sin ^(2) alpha + cos ^(2) (alpha + beta) + 2 sin alpha sin betacos(alpha+beta) then (d^(3)y)/(dalpha^(3))=?

If 3costheta + 4sin theta = A sin (theta +alpha) , then values of A and alpha are

Find the length of perpendicular from the point (a cos alpha, a sin alpha) to the line x cos alpha+y sin alpha=p .

If sin alpha+ sin beta+ sin gamma=3, then sin^3alpha+sin^3beta+sin^3 gamma=

Solve: sin3alpha=4sinalphasin(x+alpha)sin(x-alpha),w h e r ealpha!=npi,n in Z

If f(x) = |{:(cos (x+alpha),cos(x+beta),cos(x+gamma)),(sin (x+alpha),sin(x+beta),sin(x+gamma)),(sin(beta+gamma),sin(gamma+alpha),sin(alpha+beta)):}| then f(theta)-2f(phi)+f(psi) is equal to

If x sin alpha = y cos alpha, prove that : x/(sec 2alpha) + y/(cosec 2 alpha) = x

If 3 sin alpha=5 sin beta , then (tan((alpha+beta)/2))/(tan ((alpha-beta)/2))=

If x=sin(alpha-beta)*sin(gamma-delta), y=sin(beta-gamma)*sin(alpha-delta), z=sin(gamma-alpha) *sin(beta-delta) , then :