2.
(4+6j)(1.5+j3/2)(15+7j)(3−2j)=12+(18+63)j−632(45+14+7j)=[(12−63)2+(18+63)2](118+14j)([12−63−(18+63)j])=
=144−1443+108+324+2163+1081416−7083+252+843+(168−843−2124−7083)j=
=684+7231668−6243−(1956+7923)j=57+63139−523−57+63163+663j
3.
k=3∑∞6k8−k4k+2−3k+3
k→∞lim∣akak+1∣=k→∞lim∣6k+18−k−14k+3−3k+48−k4k+2−3k+36k∣=
=k→∞lim∣6(24−k−3k+3)23−k−3k+4∣=63=21<1
The series is convergent.
It can be represented as two geometric series:
k=3∑∞6k8−k4k+2−3k+3=k=3∑∞12k16−k=3∑∞2k27=
=12316(1−1/121)−2327(1−1/21)=−3962669=−6.74
1.
i)
∫Cz21dz=∫01(−1+(1+i)t)21+idt=−−1+(1+i)t1∣01=−1−1/i=−1+i
ii)
∫Cz21dz=∫ππ/2e2iθ1iedθ=−e−iθ∣ππ/2=−1+i
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