What is the principal value of sec^-1(2)?

Inverse Trigonometric Functions · Question 35 of 120

Question 35

EasyOriginal question

What is the principal value of $\sec^{-1}\left(2\right)$ ?

- \frac{\pi}{3}

Correct answerYour answer

\frac{\pi}{6}

Correct answerYour answer

\frac{\pi}{3}

Correct answerYour answer

\frac{2 \pi}{3}

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Show the answer and explanation

CorrectNot quiteAnswer C

Correct answer: C

Find the angle $\theta$ in the branch $[0, \pi] - \left\{\frac{\pi}{2}\right\}$ with $\sec \theta = 2$ .
That angle is $\frac{\pi}{3}$ .

Worth noting

$\frac{\pi}{6}$ has cosecant 2; secant 2 means cosine $\frac{1}{2}$ .

Ten questions from Inverse Trigonometric Functions, at your own pace.

Ten questions from Inverse Trigonometric Functions, at your own pace.