English

Solve the Following Equation: Tan X + Tan 2 X = Tan 3 X - Mathematics

Advertisements
Advertisements

Question

Solve the following equation:

\[\tan x + \tan 2x = \tan 3x\]
Sum

Solution

Given:

\[\tan x + \tan2x = \tan3x\]
Now, 
\[\tan x + \tan2x = \tan (x + 2x)\]
\[ \Rightarrow \tan x + \tan 2x = \frac{\tan x + \tan2x}{1 - \tan x \tan2x}\]
\[ \Rightarrow \tan x + \tan2x - \frac{\tan x + \tan2x}{1 - \tan x \tan2x} = 0\]
\[ \Rightarrow (\tan x + \tan2x) (1 - \tan x \tan2x) - (\tan x + \tan2x) = 0\]
\[ \Rightarrow (\tan x + \tan 2x) (1 - \tan x \tan2x - 1) = 0\]
\[ \Rightarrow (\tan x + \tan2x) ( - \tan x \tan2x) = 0\]
\[\Rightarrow \tan x + \tan 2x = 0\] or
\[\tan x \tan2x = 0\]

Now,

\[\tan x + \tan 2x = 0 \]
\[ \Rightarrow \tan x = - \tan 2x\]
\[ \Rightarrow \tan x = \tan - 2x\]
\[ \Rightarrow x = n\pi - 2x, n \in Z\]
\[ \Rightarrow 3x = n\pi \]
\[ \Rightarrow x = \frac{n\pi}{3}, n \in Z\]

And,

\[\tan x + \tan 2x = 0 \]
\[ \Rightarrow \tan x = - \tan 2x\]
\[ \Rightarrow \tan x = \tan - 2x\]
\[ \Rightarrow x = n\pi - 2x, n \in Z\]
\[ \Rightarrow 3x = n\pi \]
\[ \Rightarrow x = \frac{n\pi}{3}, n \in Z\]

∴ \[x = \frac{n\pi}{3}, n \in Z\] or

\[x = \frac{n\pi}{3}, n \in Z\]
shaalaa.com
  Is there an error in this question or solution?
Chapter 11: Trigonometric equations - Exercise 11.1 [Page 22]

APPEARS IN

RD Sharma Mathematics [English] Class 11
Chapter 11 Trigonometric equations
Exercise 11.1 | Q 5.2 | Page 22

Video TutorialsVIEW ALL [1]

RELATED QUESTIONS

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


If \[x = \frac{2 \sin x}{1 + \cos x + \sin x}\], then prove that

\[\frac{1 - \cos x + \sin x}{1 + \sin x}\] is also equal to a.

Find x from the following equations:
\[cosec\left( \frac{\pi}{2} + \theta \right) + x \cos \theta \cot\left( \frac{\pi}{2} + \theta \right) = \sin\left( \frac{\pi}{2} + \theta \right)\]


Prove that:
\[\sin \frac{13\pi}{3}\sin\frac{2\pi}{3} + \cos\frac{4\pi}{3}\sin\frac{13\pi}{6} = \frac{1}{2}\]


If sec \[x = x + \frac{1}{4x}\], then sec x + tan x = 

 

If tan x + sec x = \[\sqrt{3}\], 0 < x < π, then x is equal to


sin6 A + cos6 A + 3 sin2 A cos2 A =


If \[f\left( x \right) = \cos^2 x + \sec^2 x\], then


Which of the following is correct?


Find the general solution of the following equation:

\[\cos x = - \frac{\sqrt{3}}{2}\]

Find the general solution of the following equation:

\[\sec x = \sqrt{2}\]

Find the general solution of the following equation:

\[\sqrt{3} \sec x = 2\]

Find the general solution of the following equation:

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

Solve the following equation:

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

Solve the following equation:

\[\sin x + \sin 2x + \sin 3x + \sin 4x = 0\]

Solve the following equation:

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


Solve the following equation:
\[\cot x + \tan x = 2\]

 


Solve the following equation:
\[5 \cos^2 x + 7 \sin^2 x - 6 = 0\]


Solve the following equation:
3 – 2 cos x – 4 sin x – cos 2x + sin 2x = 0


Solve the following equation:
3sin2x – 5 sin x cos x + 8 cos2 x = 2


Write the number of solutions of the equation
\[4 \sin x - 3 \cos x = 7\]


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

 

If \[2 \sin^2 x = 3\cos x\]. where \[0 \leq x \leq 2\pi\], then find the value of x.


The general solution of the equation \[7 \cos^2 x + 3 \sin^2 x = 4\] is


The number of values of ​x in [0, 2π] that satisfy the equation \[\sin^2 x - \cos x = \frac{1}{4}\]


If \[e^{\sin x} - e^{- \sin x} - 4 = 0\], then x =


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

2 sin2x + 1 = 3 sin x


Solve the following equations:
sin 5x − sin x = cos 3


Solve the following equations:
cot θ + cosec θ = `sqrt(3)`


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


Choose the correct alternative:
If sin α + cos α = b, then sin 2α is equal to


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


If sin θ and cos θ are the roots of the equation ax2 – bx + c = 0, then a, b and c satisfy the relation ______.


Find the general solution of the equation 5cos2θ + 7sin2θ – 6 = 0


The minimum value of 3cosx + 4sinx + 8 is ______.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×