Consider The countor intergral a + 22. Where a ) 0 ,170 and iis complex number the with the countor C being semi - circle Use The residue theorem to evaluate the countor intergrad , and the final answer waust be dz - T eka a 2.2.2. Use the result in ( 2 21 ) to evaluate the integral Cos (kxC ) dze a2 + x2 -- &