Let \(X_1,\ldots ,X_n\) be independent, identically distributed random variables with density function \[ g(t;\theta )= \begin {cases} 0, & \text {if } -\infty <t<\theta ,\\ e^{-(t-\theta )}, & \text {if } \theta \leq t<\infty . \end {cases} \] We wish to test \(H_0:\theta \leq \theta _0\) against \(H_A:\theta >\theta _0\).
(a) Find the uniformly most powerful test of size \(\alpha \).
(b) Compute the power function.