Question

Solve
13+ ytanx = cos 3 x​

Answer 1

Answer:

Step-by-step explanation:

ANSWER

Given,

dx

dy

​

−ytanx=e

x

secx

It is a first-degree linear D.E of the form

dx

dy

​

+Py=Q

here P=−tanxQ=e

x

secx

I.F=e

∫pdx

=e

∫−tanxdx

=e

−log∣secx∣

=e

logcosx

=cosx

The solution is given by,

y×I.F=∫Q×I.Fdx+c

⇒y×cosx=∫e

x

secx×cosxdx+c

⇒ycosx=∫e

x

dx+c

⇒ycosx=e

x

+