Question
Find the principal values of: $\sec ^{-1}\left(\frac{-2}{\sqrt{3}}\right)$

Answer

(c) : Let $\sec ^{-1}\left(\frac{-2}{\sqrt{3}}\right)=\theta \Rightarrow \sec \theta=\frac{-2}{\sqrt{3}}=-\sec \frac{\pi}{6}$
$
\begin{aligned}
& =\sec \left(\pi-\frac{\pi}{6}\right)=\sec \frac{5 \pi}{6} \\
\Rightarrow & \theta=\frac{5 \pi}{6} \in[0, \pi]-\left\{\frac{\pi}{2}\right\}
\end{aligned}
$
$\therefore \quad$ Principal value of $\sec ^{-1}\left(\frac{-2}{\sqrt{3}}\right)$ is $\frac{5 \pi}{6}$.

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

The equation $x^2- x - 2 = 0$ in three dimensional space is represented by:
What is the general solution of the differential equation $e ^{ y ^{\prime}}= x ?$
If $\text{A}=\begin{bmatrix}\alpha&\beta\\\gamma&-\alpha\end{bmatrix}$ is such that $A^2 = I,$ then$:$
If $\text{A}=\begin{bmatrix}2&0&-3\\4&3&1\\-5&7&2\end{bmatrix}$ is expressed as the sum of a symmetric and skew-symmetric matrix, then the symmetric matrix is:
  1. $\begin{bmatrix}2&2&-4\\2&3&4\\-4&4&2\end{bmatrix}$
  2. $\begin{bmatrix}2&4&-5\\0&3&7\\-3&1&2\end{bmatrix}$
  3. $\begin{bmatrix}4&4&-8\\4&6&8\\-8&8&4\end{bmatrix}$
  4. $\begin{bmatrix}1&0&0\\0&1&0\\0&0&1\end{bmatrix}$
Mark the correct alternative in the following question:The probability of guessing correctly at least 8 out of 10 answers of a true false type examination is:
The length of the perpendicular drawn from the point (4, -7, 3) on the y-axis is:
Let $X$ be a discrete random variable. Then the variance of $X$ is:
The probabilities of a student getting I, II and III division in an examination are $\frac{1}{10},\frac{3}{5}$ and $\frac{1}{4}$ respectively. The probability that the student fails in the examination is.
$\int\frac{\text{x}^9}{(4\text{x}^2+1)^6}\text{ dx}$ is equal to:
  1. $\frac{1}{5\text{x}}\Big(4+\frac{1}{\text{x}^2}\Big)^{-5}+\text{C}$
  2. $\frac{1}{5}\Big(4+\frac{1}{\text{x}^2}\Big)^{-5}+\text{C}$
  3. $\frac{1}{10\text{x}}\Big(\frac{1}{\text{x}^2}+4\Big)^{-5}+\text{C}$
  4. $\frac{1}{10}\Big(\frac{1}{\text{x}^2}+4\Big)^{-5}+\text{C}$
Three integers are chosen at random from the first 20 integers. The probability that their product is even is,