COS cos 20 + i sin complex 2(cos 120 + i sin 120 m of the number 4(cos 40 + i sin 40) num 54. cos(5 7/3) + i sin(5 75/ COS TT + i sin or 82 (con D + i sin 070 5(cos 4.3 + i sin 4.3) 83 03 - 2if 56. 4(cos 2.1 + i sin 2.1) 84. 143 - 48 12(cos 52 + i sin 520) 57. 3(cos 1 10 + i sin 1109) 86. [20cos 108 + 1 sin 10% 6(cos 40 + i sin 40) 58. 7(cos 100 + i sin 1009) 88. 3 com - 1 5mm ) In Exercises 59-66, (a) write the trigonometric forms of the complex numbers, (b) perform the indicated operation In Exercises 89-104, Cal use the theorem on page using the trigonometric forms, and (c) perform the the indicated roots of the complex number, indicated operation using the standard forms, and check each of the roots graphically, and (c) write each in standard form. your result with that of part (b). 89. Square roots of S(cos 120 # I sin 1207) 59. (2 + 2i) (1 - i) 60. (3 + 1) (1 + i ) 90. Square roots of 16/cos 6of + i sin 60) 61. -2i(1 + i) 62. 4(1 - 3i) 91. Cube roots of 8 cos 27 + 1sin 3 3+ 4i 64. 1 + 3i represent the 63. 1 - V3i 6 - 3i 92. Fifth roots of 32 cos - i sin 5 93. Square roots of - 25i IT 65. 94. Fourth roots of 625i + i sin- 2+ 3i 95. Cube roots of - 125(1 + 3i) 4i 96. Cube roots of -4 2(1 - 1) 66. -4+ 2i 97. Fourth roots of 16 98. Fourth roots of i In Exercises 67-70, sketch the graph of all complex numbers 99. Fifth roots of 1 z?, 23, andz z satisfying the given condition. 100. Cube roots of 1000 101. Cube roots of - 125 67. |2 = 2 102. Fourth roots of -4 68. z =3 103. Fifth roots of 128(-1 + i) 3i 104. Sixth roots of 64i 69. 0 = 6 70. 0 = 5 T 4