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Question : 20 of 160
Marks:
+1,
-0
Solution:
Coefficient of
x6 in
(x−2)2(1+2x)−2‌=(x2−4x+4)(1−4x+‌+.‌−‌| 2(−2−1)(−2−2)×8x3 |
| 6 |
+‌‌| −2(−2−1)(−2−2)(−2−3)×16x4 |
| 24 |
+‌−‌| 2(−2−1)(−2−2)(−2−3)(−2−4)×32x5 |
| 5! |
+‌−‌| 2(−2−1)(−2−2)(−2−3)(−2−4)(−2−5)×64x6) |
| 6! |
So, coefficient of
x6 equals to
=‌‌×(−2)×(−3)×(−4)×(−5)‌‌(−2)×(−3)×(−4)×(−5)×(−6)+‌‌×−2×(−3)×−4×−5×(−6)×−7=‌2640
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