第1979题：二级结论
利用上一题的结果计算不定积分 ∫x2+5x2−1dx\int \dfrac{x^2+5}{x^2-1}dx∫x2−1x2+5dx
A. x−2ln∣x−1x+1∣+Cx-2 \ln \Big | \dfrac{x-1}{x+1} \Big |+Cx−2ln∣∣∣x+1x−1∣∣∣+C
B. x+2ln∣x−1x+1∣+Cx+2 \ln \Big | \dfrac{x-1}{x+1} \Big |+Cx+2ln∣∣∣x+1x−1∣∣∣+C
C. x−3ln∣x−1x+1∣+Cx-3 \ln \Big | \dfrac{x-1}{x+1} \Big |+Cx−3ln∣∣∣x+1x−1∣∣∣+C
D. x+3ln∣x−1x+1∣+Cx+3 \ln \Big | \dfrac{x-1}{x+1} \Big |+Cx+3ln∣∣∣x+1x−1∣∣∣+C
