∫1/(1-x^4)dx=∫1/(1+x²)(1-x²)dx=[∫1/(1+x²)+1/(1-x²)dx]/2=[∫1/(1+x²)dx]/2+[∫1/(1-x²)dx]/2=[∫1/(1+x²)dx]/2+[∫1/(1+x)(1-x)dx]/2=[∫1/(1+x²)dx]/2+[∫1/(1+x)+1...