complex numbers class work - content.njctl.org
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Pre-Calc Polar & Complex #s ~1~ NJCTL.org
Complex Numbers β Class Work
Simplify using i.
1. ββ16 2. ββ36π4 3. ββ8π2
4. ββ32π₯6π¦7 5. ββ16 β ββ25 6. ββ8 β ββ10
7. 3π β 4π β 5π 8. β2π β 4π β β6π β 8π 9. π9
10. π22 11. π75
Complex Numbers β Homework
Simplify using i.
12. ββ81 13. ββ121π8 14. ββ18π6
15. ββ48π₯5π¦6 16. ββ9 β ββ4 17. ββ12 β ββ75
18. 2π β 5π β 7π 19. βπ β β3π β β5π β β7π 20. π10
21. π23 22. π72
ππ ππππ πππβπ
ππππππβππ βππ βπβπ
βπππ πππ π
βπ βπ
ππ πππππ ππππβπ
ππππππβππ βπ βππ
βπππ πππ βπ
βπ π
Pre-Calc Polar & Complex #s ~2~ NJCTL.org
Adding, Subtracting, and Multiplying Complex Numbers β Class Work
Simplify
23. (6 + 5π) + (4 + 3π) 24. (7 + 4π) + (β2 β 2π)
25. (β3 β 2π) + (3 β π) 26. (6 + 5π) β (4 + 3π)
27. (7 + 4π) β (β2 β 2π) 28. (β3 β 2π) β (3 β π)
29. 5(4 β 2π) 30. 2π(β6 + π)
31. (6 + 5π)(4 + 3π) 32. (7 + 4π)(β2 β 2π)
33. (β3 β 2π)(3 β π) 34. (8 β 3π)(1 β π)
35. (4 β 2π)2 36. (β6 + π)2
ππ + ππ π + ππ
βππ π + ππ
π + ππ βπ β π
ππ β πππ βπ β πππ
π + πππ βπ β πππ
βππ β ππ π β πππ
ππ β πππ ππ β πππ
Pre-Calc Polar & Complex #s ~3~ NJCTL.org
Adding, Subtracting, and Multiplying Complex Numbers β Homework
Simplify
37. (2 + 3π) + (8 + 2π) 38. (4 + 9π) + (β4 β 9π)
39. (10 β 7π) + (5 β 3π) 40. (2 + 3π) β (8 + 2π)
41. (4 + 9π) β (β4 β 9π) 42. (10 β 7π) β (5 β 3π)
43. 6(5 β 6π) 44. 2π(4 β 3π)
45. (2 + 3π)(8 + 2π) 46. (4 + 9π)(β4 β 9π)
47. (10 β 7π)(5 β 3π) 48. (β6 β π)(2 β 7π)
49. (6 β 3π)2 50. (β7 + 2π)2
ππ + ππ π
ππ β πππ βπ + π
π + πππ π β ππ
ππ β πππ π + ππ
ππ + πππ ππ β πππ
ππ β πππ βππ + πππ
ππ β πππ ππ β πππ
Pre-Calc Polar & Complex #s ~4~ NJCTL.org
Dividing Complex Numbers β Class Work
Simplify
51. 2
π 52.
3
4π 53.
β2
3π
54. 2+π
π 55.
2
1+π 56.
3
2βπ
57. 2+π
3+π 58.
4βπ
3β2π
Dividing Complex Numbers β Homework
Simplify
59. 3
π 60.
2
5π 61.
β4
7π
62. 4βπ
π 63.
8
3+π 64.
2π
4βπ
65. 2βπ
2+3π 66.
5βπ
4β3π
βππ βπ
ππ
π
ππ
π β ππ π β π π+ππ
π
π+π
ππ
ππ+ππ
ππ
βππ βπ
ππ
π
ππ
βπ β ππ ππβππ
π
βπ+ππ
ππ
πβππ
ππ
ππ+πππ
ππ
Pre-Calc Polar & Complex #s ~5~ NJCTL.org
Graphing Complex Numbers β Class Work
Determine the quadrant of each of the following.
67. 9 β 3i 68. -2 + 4i
69. (5 + 4i) β (6 β 3i) 70. -3i(4 β 5i)
71. (2 + 3i)2 72. 3βi
i
73. 2
4+i 74.
5β3i
2+4i
Homework
Determine the quadrant of each of the following.
75. -7 β 3i 76. 5 - 4i
77. (3 + 2i) β (-5 + 4i) 78. (3 β i)(-4 + 5i)
79. (-1 + 5i)2 80. β2βi
3i
81. 4
3βi 82.
β6+2i
3β2i
IV II
II III
II III
IV III
III IV
IV II
III II
I III
Pre-Calc Polar & Complex #s ~6~ NJCTL.org
Polar Properties β Class Work
Name the point three other ways using polar coordinates.
83. [5,Ο
2] 84. [β4,
2Ο
3]
85. [3,β4Ο
7] 86. [β6,0]
Convert the point to rectangular form.
87. [5,Ο
2] 88. [β4,
2Ο
3]
89. [3,β4Ο
7] 90. [β6,0]
Convert the point to polar form.
91. ( 3, 6) 92. (-4, 2)
93. (1, 0) 94. (7, 7)
(βπ,ππ
π) , (π, β
ππ
π) , (βπ, β
π
π) (π,
ππ
π) , (π, β
π
π) , (βπ, β
ππ
π)
(βπ, βπππ
π) , (βπ,
ππ
π) , (π,
πππ
π) (π, π ), (π, βπ ), (βπ, ππ )
(π, π) (π, βπβπ)
(βπ. ππππ, βπ. ππππ) (βπ, π)
(πβπ, ππ. ππ) (πβπ, πππ. ππ)
(π, ππ) (πβπ, πππ)
Pre-Calc Polar & Complex #s ~7~ NJCTL.org
Polar Properties β Homework
Name the point three other ways using polar coordinates.
95. [7,Ο
3] 96. [β6,
2Ο
5]
97. [2,β3Ο
5] 98. [3, π]
Convert the point to rectangular form.
99. [7,Ο
3] 100. [β6,
2Ο
5]
101. [2,β3Ο
5] 102. [3, Ο]
Convert the point to polar form.
103. ( -3, 2) 104. (-7, -8)
105. (5, 10) 106. (-7, 0)
(π, βππ
π) , (βπ,
ππ
π) , (βπ, β
ππ
π) (π,
ππ
π) , (βπ, β
ππ
π) , (π, β
ππ
π)
(π,ππ
π) , (βπ,
ππ
π) , (βπ, β
ππ
π) (βπ, π), (βπ, ππ ), (π, βπ )
(π. π, π. πππ) (βπ. πππ, βπ. πππ)
(βπ. πππ, βπ. πππ) (βπ, π)
(βππ, πππ. ππ)
(πβπ, ππ. ππ)
(βπππ, πππ. ππ)
(π, ππππ)
Pre-Calc Polar & Complex #s ~8~ NJCTL.org
Geometry of Complex Numbers β Class Work
Let a =3 + 4i and b= -2 + 5i, perform the operation and write the answer in complex, rectangular,
polar, and trigonometric forms.
107. a + b 108. b β a
109. ab 110. a2
111. b2 112. 3a2b
113. π = 4(πππ π
4+ ππ ππ
π
4) and π = 3(πππ
7π
6+ ππ ππ
7π
6), find ab.
114. π = [5,2π
5] and π = [3,
4π
6], find cd. 115. Find z if z[10, 80Β°]= [15, 140Β°]
π + ππ
(π, π)
(βππ, ππ. ππ)
βππ(ππ¨π¬ ππ. π + π π¬π’π§ ππ. π)
βπ + π
(βπ, π)
(βππ, πππ. ππ)
βππ(ππ¨π¬ πππ. π + π π¬π’π§ πππ. π)
βππ + ππ
(βππ, π)
(πβππ, πππ. ππ)
πβππ(ππ¨π¬ πππ. π + π π¬π’π§ πππ. π)
βπ + πππ
(βπ, ππ)
(ππ, πππ. ππ)
ππ(ππ¨π¬ πππ. π + π π¬π’π§ πππ. π)
βππ β πππ
(βππ, βππ)
(ππ, πππ. ππ)
ππ(ππ¨π¬ πππ. π + π π¬π’π§ πππ. π)
βπππ β ππππ
(βπππ, βπππ)
(ππβππ, πππ. ππ)
ππβππ(ππ¨π¬ πππ. π + π π¬π’π§ πππ. π)
ππ(ππ¨π¬πππ
ππ+ π π¬π’π§
πππ
ππ)
(ππ,πππ
ππ) π = (
π
π, πππ)
Pre-Calc Polar & Complex #s ~9~ NJCTL.org
Geometry of Complex Numbers β Homework
Let a =7 - 3i and b= -3 - 8i, perform the operation and write the answer in complex, rectangular,
polar, and trigonometric forms.
116. a + b 117. a β b
118. b β a 119. ab
120. a2 121. b2
122. 3a 123. 3a2b
124. π = 7(πππ π
3+ ππ ππ
π
3) and π = 2(πππ
5π
6+ ππ ππ
5π
6), find ab.
125. π = [12,7π
4] and π = [. 5,
5π
3], find cd. 126. Find z if z[20, 100Β°]= [15, 140Β°]
π β πππ
(π, βππ)
(βπππ, ππππ)
βπππ(ππ¨π¬ πππ + π π¬π’π§ πππ)
ππ + ππ
(ππ, π)
(πβπ, ππ. ππ)
πβπ(ππ¨π¬ ππ. π + π π¬π’π§ ππ. π)
βππ β ππ
(βππ, βπ)
(πβπ, πππ. ππ)
πβπ(ππ¨π¬ πππ. π + π π¬π’π§ πππ. π)
βππ β πππ
(βππ, βππ)
(ππ. π, πππ. ππ)
ππ. π(ππ¨π¬ πππ. π + π π¬π’π§ πππ. π)
ππ β πππ
(ππ, βππ)
(ππ, πππ. ππ)
ππ(ππ¨π¬ πππ. π + π π¬π’π§ πππ. π)
βππ + πππ
(βππ, ππ)
(ππ, πππ. ππ)
ππ(ππ¨π¬ πππ. π + π π¬π’π§ πππ. π)
ππ β ππ
(ππ, βπ)
(πβππ, πππ. ππ)
πβππ(ππ¨π¬ πππ. π + π π¬π’π§ πππ. π)
βππππ β ππππ
(βππππ, βπππ)
(πππβππ, ππππ)
πππβππ(ππ¨π¬ πππ + π π¬π’π§ πππ)
ππ(ππ¨π¬ππ
π+ π π¬π’π§
ππ
π)
(π,πππ
ππ) (
π
π, πππ)
Pre-Calc Polar & Complex #s ~10~ NJCTL.org
Polar Equations and Graphs β Class Work
127. Draw the graph of π = sin π 128. Draw the graph of π = 3 + πππ π
129. Draw the graph of π = 5 130. Draw the graph of π =2π
3
131. Draw the graph of ππππ π = 6
Pre-Calc Polar & Complex #s ~11~ NJCTL.org
Polar Equations and Graphs β Homework
132. Draw the graph of π = πππ π 133. Draw the graph of π = 4 + π πππ
134. Draw the graph of π = β5 135. Draw the graph of π =3π
4
136. Draw the graph of ππ πππ = β6
Pre-Calc Polar & Complex #s ~12~ NJCTL.org
Rose Curves and Spirals β Class Work
137. How many petals and what is a petals length for π = 4πππ 3π? Draw the graph.
138. How many petals and what is a petals length for π = 5π ππ6π? Draw the graph.
139. How many petals and what is a petals length for π = 2πππ 4π? Draw the graph.
140. How many petals and what is a petals length for π = 7πππ 5π? Draw the graph.
141. What kind of spiral is π = 3π? 142. What kind of spiral is π = 2π + 2?
3 petals
length: 4
12 petals
length: 5
8 petals
length: 2
5 petals
length: 7
Logarithmic Archimedes
Pre-Calc Polar & Complex #s ~13~ NJCTL.org
Rose Curves and Spirals β Homework
143. How many petals and what is a petals length for π = 6πππ 2π? Draw the graph.
144. How many petals and what is a petals length for π = 4π ππ7π? Draw the graph.
145. How many petals and what is a petals length for π = 3πππ 6π? Draw the graph.
146. How many petals and what is a petals length for π = 5πππ 3π? Draw the graph.
147. What kind of spiral is π = 2π? 148. What kind of spiral is π = 3π + 1?
4 petals
length: 6
7 petals
length: 4
12 petals
length: 3
3 petals
length: 5
Logarithmic Archimedes
Pre-Calc Polar & Complex #s ~14~ NJCTL.org
Powers of Complex Numbers β Class Work
Compute the given power and write your answer in the original form.
149. ([3,60Β°])5 150. (4 (πππ π
5+ ππ ππ
π
5))
7
151. (5 β 6π)6 152. (β5,9)8
153. If a tenth root of w is (3,8) what is w?
Homework
Compute the given power and write your answer in the original form.
154. ([9,80Β°])7 155. (5 (πππ 4π
3+ ππ ππ
4π
3))
9
156. (β4 + 7π)8 157. (β7, β3)10
158. If a sixth root of w is 7(πππ 0 + ππ ππ0) what is w?
(πππ, ππππ) πππππ( ππ¨π¬ππ
π+ π π¬π’π§
ππ
π)
ππππππ + πππππππ (βππππππππ, βπππππππππ)
(ππππππππππ, βπππππππππ)
(πππππππ, ππππ) πππππππ( ππ¨π¬ ππ + π π¬π’π§ ππ )
βπππππππ β πππππππππ (βπππππππππ, βπππππππππ)
ππππππ(ππ¨π¬ π + π π¬π’π§ π)
Pre-Calc Polar & Complex #s ~15~ NJCTL.org
Roots of Complex Numbers β Class Work
Find the given roots and write the answer in the same form as the original.
159. fifth root of [3,60Β°] 160. fourth root of 4 (πππ π
5+ ππ ππ
π
5)
161. sixth root of 5 β 6π 162. eighth root of (β5,9)
163. a to the fourth is β3(cos 20Β° + ππ ππ 20Β°), find a
(π. πππ, πππ)
(π. πππ, πππ)
(π. πππ, ππππ)
(π. πππ, ππππ)
(π. πππ, ππππ)
π. πππ (ππ¨π¬π
ππ+ π π¬π’π§
π
ππ)
π. πππ (ππ¨π¬πππ
ππ+ π π¬π’π§
πππ
ππ)
π. πππ (ππ¨π¬πππ
ππ+ π π¬π’π§
πππ
ππ)
π. πππ (ππ¨π¬πππ
ππ+ π π¬π’π§
πππ
ππ)
. πππ + π. ππππ
β. πππ + π. πππ
βπ. πππ+. ππππ
β. πππ β π. ππππ
. πππ β π. πππ
π. πππβ. ππππ
(π. πππ, π. πππ)
(. πππ, π. πππ)
(β. πππ, π. πππ)
(βπ. πππ, π. πππ)
(βπ. πππ, βπ. πππ)
(β. πππ, βπ. πππ)
(. πππ, βπ. πππ)
(β. πππ, π. πππ)
π. πππ(ππ¨π¬ πΒ° + π π¬π’π§ πΒ°)
π. πππ(ππ¨π¬ ππΒ° + π π¬π’π§ ππΒ°)
π. πππ(ππ¨π¬ πππΒ° + π π¬π’π§ πππΒ°)
π. πππ(ππ¨π¬ πππΒ° + π π¬π’π§ πππΒ°)
Pre-Calc Polar & Complex #s ~16~ NJCTL.org
Homework
Find the given roots and write the answer in the same form as the original.
164. fifth root of [9,80Β°] 165. fourth root of 5 (πππ 4π
3+ ππ ππ
4π
3)
166. sixth root of (β4 + 7π) 167. eighth root of (β7, β3)
168. a to the sixth is β3(cos 30Β° + ππ ππ 30Β°), find a
(π. ππ, πππ)
(π. ππ, πππ)
(π. ππ, ππππ)
(π. ππ, ππππ)
(π. ππ, ππππ)
π. πππ (ππ¨π¬π
π+ π π¬π’π§
π
π)
π. πππ (ππ¨π¬ππ
π+ π π¬π’π§
ππ
π)
π. πππ (ππ¨π¬ππ
π+ π π¬π’π§
ππ
π)
π. πππ (ππ¨π¬πππ
π+ π π¬π’π§
πππ
π)
(π. πππ + π. ππππ)
(π. πππ + π. ππππ)
(βπ. πππ + π. ππππ)
(βπ. πππ β π. ππππ)
(βπ. πππ β π. ππππ)
(π. πππ β π. ππππ)
(π. πππ, π. πππ)
(π. πππ, π. πππ)
(βπ. πππ, π. πππ)
(βπ. πππ, π. πππ)
(βπ. πππ, βπ. πππ)
(βπ. πππ, βπ. πππ)
(π. πππ, βπ. πππ)
(π. πππ, βπ. πππ)
π. πππ(ππ¨π¬ πΒ° + π π¬π’π§ πΒ°)
π. πππ(ππ¨π¬ ππΒ° + π’ π¬π’π§ ππΒ°)
π. πππ(ππ¨π¬ πππΒ° + π’ π¬π’π§ πππΒ°)
π. πππ(ππ¨π¬ πππΒ° + π’ π¬π’π§ πππΒ°)
π. πππ(ππ¨π¬ πππΒ° + π’ π¬π’π§ πππΒ°)
π. πππ(ππ¨π¬ πππΒ° + π’ π¬π’π§ πππΒ°)
Pre-Calc Polar & Complex #s ~17~ NJCTL.org
Polar and Complex Numbers Unit Review
Multiple Choice
1. Simplify: β4π β 6π β β2π β βπ
a. -48i
b. 48i
c. -48
d. 48
2. Simplify: (6 β π)2
a. 35 + 12i
b. 35 - 12i
c. 37 - 12i
d. 37 + 12i
3. Simplify: 3βπ
4β2π
a. 7
10+
1
10i
b. 7
6+
1
6i
c. 7
10β
1
10i
d. 7
6β
1
6i
4. What quadrant is (6 + 2i) β (7 β 4i) in?
a. I
b. II
c. III
d. IV
5. What quadrant is (3 - 5i)2 in?
a. I
b. II
c. III
d. IV
6. What quadrant is 3βπ
4β2π in?
a. I
b. II
c. III
d. IV
7. Which of the point choices listed are not equal to: [5,Ο
2]
a. (0,5)
b. 5(πππ π
2+ ππ ππ
π
2)
c. [β5,3Ο
2]
d. they are all equivalent
C
C
A
B
C
A
D
Pre-Calc Polar & Complex #s ~18~ NJCTL.org
8. Convert the point to rectangular form: [4,Ο
3]
a. (2,β3
2)
b. (β3
2, 2)
c. (2,β3)
d. (2,2β3)
9. Convert the point to polar form: ( 2.5 , 6)
a. (6.5, 0.395)
b. (6.5 , 1.176Β°)
c. (6.5 , 22.620Β°)
d. (6.5, 67.380Β°)
10. Let a =8 - 2i and b= -5 - 7i, which of the following is not a + b?
a. (3,-9)
b. [3β10, β71.565]
c. 10(cos 288.435Β° + i sin 288.435Β°)
d. β( -3 + 9i)
11. π = 6(πππ π
4+ ππ ππ
π
4) and π = β3(πππ
5π
3+ ππ ππ
5π
3), find ab.
a. β18(πππ 6π
7+ ππ ππ
6π
7)
b. β18(πππ 5π
12+ ππ ππ
5π
12)
c. β18(πππ 17π
12+ ππ ππ
17π
12)
d. β18(πππ 23π
12+ ππ ππ
23π
12)
12. How many petals and what is a petals length for π = 4πππ 8π?
a. 4 petals, length 8
b. 8 petals, length 4
c. 8 petals, length 8
d. 16 petals, length 4
13. Compute: (7 β 3π)6
a. ( 195112, 220.809Β°)
b. ( 45.694, 220.809Β°)
c. ( 195112, 1.871π)
d. ( 45.694, 1.871π)
14. If a tenth root of w is [5,2π
3], what is w?
a. [50,20Ο
3]
b. [9765625,20Ο
3]
c. [50,4Ο
3]
d. [9765625,4Ο
3]
D
D
C
D
D
A
B
Pre-Calc Polar & Complex #s ~19~ NJCTL.org
15. Find the third root of 27 (πππ π
2β ππ ππ
π
2)
a. [3,Ο
6]
b. [3,Ο+4kΟ
6] for k β {1,2}
c. [3,4+kΟ
6] for k β {1,2,3}
d. [3,Ο+4kΟ
6] for k β {0,1,2}
Extended Response
16. Let a =8 - 2i and b= -5 - 7i.
a. Find 3a2b.
b. How far from the origin is a + b?
c. What is the angle of rotation of a+b?
17. Write an equation
a. for a rose curve with 8 petals of length 5
b. for a rose curve with 5 petals of length 6
c. a Spiral of Archimedes with 6π between the spirals
D
βππππ β ππππ
πβππ
πππ. πππ
π = π ππ¨π¬ ππ½ ππ π = π π¬π’π§ ππ½
π = π ππ¨π¬ ππ½ ππ π = π π¬π’π§ ππ½
π = ππ½ + π πππ π β₯ π