Q.

Let y=y(x) be the solution curve of the differential equation (1+x2)dy+(y-tan-1x)dx=0, y(0)=1. Then the value of y(1) is:        [2026]

1 4eπ/4-π2-1  
2 2eπ/4+π4-1  
3 4eπ/4+π2-1  
4 2eπ/4-π4-1  

Ans.

(2)

dydx+yx2+1=tan-1xx2+1

I.F.=etan-1x

y×etan-1x=etan-1x·tan-1x1+x2dx

y×etan-1x=tan-1x(etan-1x)-etan-1x+c

y(0)=1  c=2

y(1)=2eπ/4+π4-1