A acc May 2010 9 0 May 12, 2010 #1 In the expansion of (x-(3/x^2)^9 find the following: a) the term containing x6 b) the constant term This is my last question, I swear!

In the expansion of (x-(3/x^2)^9 find the following: a) the term containing x6 b) the constant term This is my last question, I swear!

mr fantastic MHF Hall of Fame Dec 2007 16,948 6,768 Zeitgeist May 12, 2010 #2 acc said: In the expansion of (x-(3/x^2)^9 find the following: a) the term containing x6 b) the constant term This is my last question, I swear! Click to expand... The general term is \(\displaystyle {9 \choose r} x^{9 - r} \left( -\frac{3}{x^2}\right)^r = {9 \choose r} (-3)^r x^{9 - r} x^{-2r} = {9 \choose r} (-3)^r x^{9 - 3r}\). a) You require the coefficient of the power of x corresponding to 9 - 3r = 6. b) You require the coefficient of the power of x corresponding to 9 - 3r = 0.

acc said: In the expansion of (x-(3/x^2)^9 find the following: a) the term containing x6 b) the constant term This is my last question, I swear! Click to expand... The general term is \(\displaystyle {9 \choose r} x^{9 - r} \left( -\frac{3}{x^2}\right)^r = {9 \choose r} (-3)^r x^{9 - r} x^{-2r} = {9 \choose r} (-3)^r x^{9 - 3r}\). a) You require the coefficient of the power of x corresponding to 9 - 3r = 6. b) You require the coefficient of the power of x corresponding to 9 - 3r = 0.