please help me to answer this step by step., differential equation,
in Calculus Answers by

Your answer

Your name to display (optional):
Privacy: Your email address will only be used for sending these notifications.
Anti-spam verification:
To avoid this verification in future, please log in or register.

1 Answer

Let y=pq where p and q are functions of x.

dy/dx=pq'+qp' and dy/dx=pq+e^x/x replacing y in the given DE by pq.

Equating these two expressions for dy/dx, q=q' (dq/dx=q; dq/q=dx; ln(q)=x; q=e^x)

qp'=e^xp'=e^x/x; dp/dx=1/x; dp=dx/x; p=ln(x).

y=pq=ke^xln(x) (k=constant of integration); but y=0 when x=e, so 0=ke^e and k=0.

y=e^xln(x)

CHECK: dy/dx=e^x/x+e^xln(x)=e^x/x+y; dy/dx-y=e^x/x

 

by Top Rated User (1.2m points)

Related questions

9 answers
0 answers
asked Mar 22, 2014 in Other Math Topics by Keys Lee | 668 views
11 answers
asked May 31, 2013 in Calculus Answers by anonymous | 2.6k views
8 answers
asked Jan 19, 2013 in Calculus Answers by anonymous | 1.7k views
13 answers
1 answer
1 answer
1 answer
16 answers
2 answers
asked Jan 29, 2016 in Calculus Answers by John | 6.9k views
Welcome to MathHomeworkAnswers.org, where students, teachers and math enthusiasts can ask and answer any math question. Get help and answers to any math problem including algebra, trigonometry, geometry, calculus, trigonometry, fractions, solving expression, simplifying expressions and more. Get answers to math questions. Help is always 100% free!
87,516 questions
100,279 answers
2,420 comments
731,849 users