miscalculation

from Two Snuke correct

• error
• 
• I see!
  • $J = \frac{2x^2}{(1-x)^3}$
  • Did (1-x)^3 correspond to taking the difference three times?
  • $4F = G + J = \frac{1}{1-x^2} + \frac{2x^2}{(1-x)^3} = \frac{-(2 x^3 + 3 x^2 - 2 x + 1)}{((x - 1)^3 (x + 1))}$
  • Hmmm, what's with the much different shape?

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