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1a) (5, 435^o) I added 360^o
1a) (-5, 255^o) I added 180^o

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1b) (4, 11p/4) I added 2p
1b) (-4, 7p/4) I added p

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               _____
2a) r = \/ 9 + 16 = 5 and tan (4/3) = 53.1^o This is the reference angle. The angle is supposed to be in the 2nd quadrant. Subtract from 180.
Answer is   (5, 126.9^o)

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2b) Easy one. r = 4 and q = 180^o  Why?
Answer is: (4, 180^o)

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             _______
3) r = \/ 25 + 169 = 13.9 and Tan(13/5) = 1.21 in rads.
Answer is: (13.9, 1.21) 

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4a) x = 7cos 240^o = -3.5 and y = 7sin 240^o = -6.1
Answer is: (-3.5, -6.1) 

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4b) x = 3cos 142^o = -2.4 and y = 3sin 142^o = 1.8
Answer is: (-2.4, 1.8) 

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5a)  5b)           5c)  5d)      5e)  5f)            5g) 

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6) r = 3.6 and 0 = 33.7^o
Answer is: 3.6cis 33.7^o       

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7) a = 5cos 320^o and b = 5 sin 320^o
Answer is: 3.8 - 3.2i      

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8) z₁ = 5.8cis 59^o and z₂ = 7.8cis 50.2^o
a) z₁z₂ = 45.2cis 109.2^o
b) a = 45.2cos109.2^o and b = 45.2sin 109.2^o
Answer is: -14.9 + 42.7i       

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9) 9cis 120^o

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10a) z = 1.4cis 45^o and z⁶ = (1.4)⁶ cis (6)(45^o) = 7.5 cis 270^o
b) a = 7.5cos 270^o and b = 7.5sin 270^o
Answer is:  -7.5i       

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11) The three cubed roots of one are found as follows:
for k = 0,      = 1cis 120^o = -1/2 + .87i
for k = 1       = 1cis 240^o = -1/2 - .87i
for k = 2       = 1cis 360^o = 1       

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