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?
  • $4F=G+J=\frac{1}{1-x^2}+\frac{2x^2}{(1-x{)}^3}=\frac{-(2x^3+3x^2-2x+1)}{((x-1{)}^3(x+1))}$
  • Hmmm, what’s with the much different shape?

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