>>251

∫1/(0.09-x^2) dx=(1/0.6)∫{1/(0.3-x) +1/(0.3+x)}dx
=(1/0.6){-log|0.3-x|+log|0.3+x|}
=(1/0.6)・log|(0.3+x)/(0.3-x)|
lim[x→∞] log|(0.3+x)/(0.3-x)|=lim log|(1+0.3/x)/(-1+0.3/x)|
=log|-1|=0
lim[x→0.4] log|(0.3+x)/(0.3-x)|=log|0.7/(-0.1)|=log(7)