∫etan−1x1+x+x2⋅dcot−1x is equal to
−etan−1x+C
etan−1x+C
−xetan−1x+C
xetan−1x+C
I=∫etan−1x1+x+x2⋅−11+x2dx=−∫etan−1x1+x1+x2dx=−∫etan−1xdx−∫x⋅etan−1x1+x2dx integration by parts=−∫etan−1xdx−x⋅etan−1x+∫etan−1xdx+C=−x⋅etan−1x+C