Question

y"=1/(1+x^2 ) y(0)=0 y'(0)=0 решить задачу Коши

Answer 1

y'=arctgx+c1
y'(0)=arcctg0+c1=0 c1=0
y=xarctgx-1/2ln(1+x^2)+C2
y(0)=0-1/2ln1+c2=0 c2=0
y=xarctgx-1/2ln(1+x^2)