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# Find the term independent of x in the expansion of (x^2 - 1/2x)^3

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Why bother with a post grad? Are they even worth it? Have your say! 26-10-2016
1. been stuck on this question for a while now, the answer is 3/4, can someone please tell me what to do?
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Just quoting in Puddles the Monkey so she can move the thread if needed
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(Original post by Puddles the Monkey)
x
3. You want the component of the expansion with a negative exponent to cancel out with the positive exponent. X^2 has a positive exponent. Now multiplying X^2 with (-0.5x^-1)^2 will give a term independent of x (X^2 times X^-2 is 1). Now you need to consider the binomial coefficient in the expansion. B(3,1)=B(3,2)=3. 3*(-0.5)^2=3/4.
4. Check binomial theorem if you are still unsure.

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