Question
Solve the following equations:
$\tan\text{x}+\tan2\text{x}+\tan3\text{x}=0$

Answer

$\tan\text{x}+\tan2\text{x}+\frac{(\tan\text{x}+\tan2\text{x})}{1-\tan\text{x}.\tan2\text{x}}=0$
$[\tan\text{x}+\tan2\text{x}]\Big[1+\frac{1}{1-\tan\text{x}.\tan2\text{x}}\Big]=0$
$\tan\text{x}+\tan2\text{x}(2-\tan\text{x}.\tan2\text{x})=0$
$\tan\text{x}=\tan(-2\text{x})$ or $\tan\text{x}.\tan2\text{x}=0$
$\text{x}=\text{n}\pi-2\text{x}$ or $\tan\text{x}.\frac{2\tan\text{x}}{1-\tan^{2}\text{x}}=2$
$3\text{x}=\text{n}\pi$ or $\frac{2\tan^{2}\text{x}}{1-\tan^{2}\text{x}}=2$
$3\text{x}=\text{n}\pi$ or $2\tan^{2}\text{x}=2-2\tan^{2}\text{x}$
$3\text{x}=\text{n}\pi$ or $4\tan^{2}\text{x}=2$
$\text{x}=\frac{\text{n}\pi}{3}$ or $\tan^{2}\text{x}=\frac{1}{2}$
$\text{x}=\frac{\text{n}\pi}{3}$ or $\text{x}=\text{m}\pi\pm\tan^{-1}(\frac{1}{\sqrt{2}}),\text{n,m}\in\text{Z}$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

Prove that:
$\frac{\cos3\text{A}+2\cos5\text{A}+\cos7\text{A}}{\cos\text{A}+2\cos3\text{A}+\cos5\text{A}}=\frac{\cos5\text{A}}{\cos3\text{A}}$
Sketch the graphs of the following curves on the same scale and the same axes:
$\text{y}=\cos^2\text{x}$ and $\text{y}=\cos\text{x}$
Find the equations to the straight lines passing through the point (2, 3) and inclined at and angle of 45° to the line 3x + y - 5 = 0.
Prove that:
$\tan20^\circ\tan30^\circ\tan40^\circ\tan80^\circ=1$
If $\text{a}=\sec\text{x}-\tan\text{x}$ and $\text{b}=\text{cosec x}+\cot\text{x},$ then show that $\text{ab}+\text{a} - \text{b}+ 1=0.$
A man accepts a position with an initial salary of ₹ 5200 per month. It is understood that he will receive an automatic increase of ₹ 320 in the very next month and each month thereafter.
  1. Find his salary for the tenth month.
  2. What is his total earnings during the first year?
A box contains 10 red marbles, 20 blue marbles and 30 green marbles. 5 marbles are drawn at random. from the box, what is the probability that:
  1. All are blue?
  2. At least one is green?
Prove the following identities:
$\frac{1−\sin\text{x}\cos\text{x}}{\cos\text{x}(\sec\text{x}−\text{cosec}\text{x})}\cdot\frac{\sin^2\text{x}−\cos^2\text{x}}{\sin^3\text{x}\cos^3\text{x}}=\sin\text{x}$
If $A =\{p, q, r, s\}, B =\{q, s, u\}$ and $C =\{r, s, t, u\}$, then prove the following :
(i) $(A-B) \cup(A-C)=A-(B \cap C)$
(ii) $A \cap(B \cup C)=(A \cap B) \cup(A \cap C)$
(iii) $A \cup(B \cap C)=(A \cup B) \cap(A \cup C)$

In the expansion of $(1+\text{x})^{\text{n}}$ the binomial corfficients of three consecutive terms are respectively 220. 495 and 792, find the value of n.