Hello all ,

i have the equation

now i managed to find the formula for it and got to:Code:`(1+x^2)y'+y=arctgx`

where ~ is the sign for integralCode:y=e^-arctanx[~(arctanx*e^tanx*dx)/(1+x^2)]

now i'm supposed to do t=arctanX

but don't understand where i get the dt from ?

how do i find the DT is what i'm asking here

thanks to all the helpers !!