Grade Select GradeIntegral Calculus 1-x2 / (1+x2)2 where x= tan θ Akshansh Jain 13 Years agoGrade Select Grade
apoorva sagarwal13 Years ago∫1-x2/(1+x2)2 add and subtract 1 to numerator ,you get ∫2/(1+x2)2 dx - ∫1/(1+x2) dx ===> ∫2/(1+x2)2 dx-tanx+c = let x=tanθ ===> dx=sec2θ dθ ∫2/(1+tan2θ)2 sec2θ dθ -tanx+c =∫2cos2θ dθ-tanx+c =∫(cos2θ+1)dθ-tanx+c =sin2θ/2 +x-tanx+c =tanθ/1+tan2θ +x-tanx+c but x=tanθ x/(1+x2) +x-tanx+c