Q.

Integrating factor of the equation (x2+1)dydx+2xy=x2-1 is:

1 x2+1  
2 2xx2+1  
3 x2-1x2+1  
4 x2+1x2-1  

Ans.

(1)

Ans.      x2+1

Explanation:

⇒  dydx+2x1+x2y=x2-1x2+1

I.F.=e∫2x1+x2dx

       =elog(1+x2)

       =1+x2