NCERT Class XI Mathematics - Complex Numbers and Quadratic Equations - Solutions

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Question : 10
Total: 52
(−2−
1
3
i
)
3
Solution:  
(−2−
1
3
i
)
3
= (−2)3+(−
1
3
i
)
3
+ 3(−2)2(−
1
3
i
)
+3(−2)(−
1
3
i
)
2

= - 8 -
1
27
i3
- 4i -
2
3
i2
= - 8 -
1
27
(- i) - 4i -
2
3
(- 1)
= - 8 +
1
27
i
- 4i +
2
3
= (−8+
2
3
)
+(
1
27
−4
)
i

= (
−24+2
3
)
+(
1−108
27
)
i
= (
−22
3
)
+ (
−107
27
)
i
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