For which value of x is the function \(\csc^{-1}x\) not defined?

Correct answer: \(x=\frac{1}{2}\)

\(\csc^{-1}x\) is defined only for \(|x|\ge 1\), i.e. the domain is \(( -\infty,-1 ]\cup[1,\infty )\). Hence \(x=\tfrac{1}{2}\) is not allowed because \(|\tfrac{1}{2}|<1\). The other choices satisfy the domain: \(x=2\) and \(x=-3\) are valid, and \(x=-1\) is valid as an endpoint. Exam tip: memorize domains of inverse trig functions (especially arccsc/arccot) to avoid common mistakes on boundaries.