First-order differential equation

Join the discussion
Ask a follow-up here, or get your own question answered by working scientists, mathematicians and engineers — people, not an autocomplete.
Real named experts · corrections over time · the nuance an AI answer skips
1 reply · 1K views
Mathematicsss

Homework Statement


y'+tanxy=sinx

Homework Equations



integrating factor I(x)= exp{lnIsecxI}[/B]

The Attempt at a Solution


I have secxy= integral of sinx I(x)
I am not sure how to integrate that because secx is in absolute value form.[/B]
 
Physics news on Phys.org
Mathematicsss said:

Homework Statement


y'+tanxy=sinx

Homework Equations



integrating factor I(x)= exp{lnIsecxI}[/B]

The Attempt at a Solution


I have secxy= integral of sinx I(x)
I am not sure how to integrate that because secx is in absolute value form.[/B]

There are two cases: (1) the values of ##x## make ##\sec(x) > 0##; or (2) the values of ##x## make ##\sec(x) < 0##. Just analyze both cases, although you need to worry about whether the solution ##y(x)## can remain meaningful if ##x## crosses from one region to the other.