1) The modulus -amplitude form of (1−i)3(2−i)(2+i)(1+i) is A) 2cis(π−tan−143) B) 2cis(−tan−143) C) 2cis(−π+tan−143) D) 2cis(tan−143) Answer: Option AExplanation:We have, (1−i)3(2−i)(2+i)(1+i)=(1−i)2(1−i)(2−i)(1+i)(2+i) =−2i(1−i)(1−i)(2−i)(2−i)(1+i)(1−i)(2+i)(2−i) =−2i(−2i)(3−4i)2.5=−2(35−4i5) =−2(−35+45i) 2cis(π−tan−143)