Questions: Find the exact value of the real number y if it exists. Do not use a calculator.
y = csc^(-1)(-1)
Select the correct answer below and, if necessary, fill in the answer box to complete your choice.
A. y = csc^(-1)(-1) =
(Simplify your answer. Type an exact answer, using π as needed. Use integers or fractions for any numbers in the expression.)
B. csc^(-1)(-1) does not exist.
Transcript text: Find the exact value of the real number $y$ if it exists. Do not use a calculator.
\[
y=\csc ^{-1}(-1)
\]
Select the correct answer below and, if necessary, fill in the answer box to complete your choice.
A. $y=\csc ^{-1}(-1)=$ $\square$
(Simplify your answer. Type an exact answer, using $\pi$ as needed. Use integers or fractions for any numbers in the expression.)
B. $\csc ^{-1}(-1)$ does not exist.
Solution
Solution Steps
Step 1: Understand the Problem
We are tasked with finding the exact value of \( y = \csc^{-1}(-1) \). The inverse cosecant function, \( \csc^{-1}(x) \), returns the angle whose cosecant is \( x \). The range of \( \csc^{-1}(x) \) is typically \( \left[-\frac{\pi}{2}, 0\right) \cup \left(0, \frac{\pi}{2}\right] \).
Step 2: Recall the Definition of Cosecant
The cosecant function is defined as:
\[
\csc(\theta) = \frac{1}{\sin(\theta)}
\]
We need to find an angle \( \theta \) such that:
\[
\csc(\theta) = -1
\]
This implies:
\[
\sin(\theta) = -1
\]
Step 3: Determine the Angle
The sine function equals \(-1\) at:
\[
\theta = \frac{3\pi}{2} + 2\pi k \quad \text{for integer } k
\]
However, the principal value of \( \csc^{-1}(x) \) lies in the range \( \left[-\frac{\pi}{2}, 0\right) \cup \left(0, \frac{\pi}{2}\right] \). The angle \( \frac{3\pi}{2} \) is not within this range, but its equivalent angle \( -\frac{\pi}{2} \) is.
Final Answer
The exact value of \( y = \csc^{-1}(-1) \) is:
\[
\boxed{y = -\frac{\pi}{2}}
\]
Thus, the correct choice is A.