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Click Next or Back to navigate through the exam. If you want to skip a question or come back to review Click Review Answer Selections anytime to jump to the review page. From that page, you can return to the e Click Exit Without Submitting to exit the exam. Your work so far will be saved. it later Question 1 of 20 : Select the best answer for the question. 1. Which of these is a complex fourth root of cos 120 + i sin 120 ? A. cos 190° + i sin 190° B. cos 220° + i sin 220° C, cos 210° + i sin 210° D. cos 200 +i sin 200 Next Review Answer Selections Search the web and Windows

Explanation / Answer

1. cos210degree + isin210 degree

4th root =e^(i*120*4)= e^(i*120*4)=e^(i*480)=e^i(270+190)=e^(i*190)=cos190degree + isin190 degree

2. dot product =-8*15-5*8=120-40=80 (A)

3. dot product =88-30=58

4.(12/(13))i +(5/13)j

5. absolute value =(14^2+8^2)^.5

(196+64)^.5=(260)^.5=2(65)^.5

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