∫1⁄1+x2+y2dx

Dear Jithu

I = ∫1⁄(1+x²+y²)  dx

I = ∫1⁄√(1+y²)²+x²)  dx 

   = 1/ √(1+y²)   tan ^-1 { x/√(1+y²)}  +  C

here y is taken as constant because nothing is given about y

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