In this exercise we have to use the knowledge of ordinary equations to determine the linear equations, in this way we find that:
1) Linear
2) Non Linear
3) Linear
4) Non linear
So from the knowledge in topics of ordinary equations we find that:
1) [tex](1-x)y"-4xy'+5y=cosx\\= Second \ order\\= linear[/tex]
2)[tex]t^5 y^4 - t^3 y" + 6y =0 \\= Second \ order\\= non \ linear[/tex]
3) [tex](d^2Y/dx^2) = \sqrt{(1+(dy/dx)^2))}\\= Second \ order\\= Linear[/tex]
4) [tex](Sin\theta)y"'- (cos\theta)y' =2\\= Third \ order\\= Non \ linear[/tex]
See more about ordinary equations at brainly.com/question/16025014
