MA460 Honors Precalculus Name Complex Numbers in Trigonometric Form Date • Write in simplified form. No calculator. 1. 3cis (17°) ! 2 cis (28° )= 2. 6 cis (83°) ! 3 cis (37°)= 3. 8 cis (33°)4 cis (18°)= 4. (!1 + i)4= 5. 4 ! 4 3 i( )5= 6. cis!4"#$%&'6= • Write in simplified form, using a calculator as little as possible. 7. Find the 3 cube roots of –16 – 16i. 8. Find the 4 fourth roots of i.9. Find the 2 square roots of 3 + 4i. (Do this with half angle identities and without a calculator.) 10. One of the 3 cube roots of z is3 + i. (a) Find the others. (b) Find z. 11. One of the 3 cube roots of z is 2 + 5i. (a) Approximate the others. (b) Find z. 12. If i and !12+32i are consecutive nth roots of a complex number z, (a) what is n? (b) what is z? 13. For some n > 1, cis(!5)is an nth root of 1. What is the least possible value of n? Explain. 14. Find all three values of(!i)2 /