應(yīng)用留數(shù)定理計(jì)算回路積分,函數(shù)f(z)在l所圍區(qū)域上是解析的,a是這區(qū)域的一個(gè)內(nèi)點(diǎn)
設(shè)函數(shù)f(z)和g(z)分別以點(diǎn)z0為m階和n階極點(diǎn),問(wèn)對(duì)于下列函數(shù)而言,z0是何種性質(zhì)的點(diǎn)? (1)f(z)g(z) (2)f(z)/g(z) (3)f(z)+g(z)