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Solve x log x dy/dx + y = 2 log x

Short answer

Divide by x log x to get linear form with integrating factor log x. Multiplying and integrating (log x)² gives the solution y = log x + c/log x.

Solve the differential equation: x log x dy/dx + y = 2 log x.

x log x dy/dx + y = 2 log x

Standard linear form

Divide by x log x:

dy/dx + y/(x log x) = 2/x

P = 1/(x log x), Q = 2/x.

Integrating factor

∫ dx/(x log x) = log(log x), so IF = log x.

Solution

y log x = ∫ (2/x) log x dx = (log x)² + c

(since ∫ (log x)/x dx = (log x)²/2)

y = log x + c/log x

(Check: y' = 1/x − c/(x (log x)²); x log x · y' = log x − c/log x; adding y = log x + c/log x gives 2 log x ✓.)

✓ Answer checked by Claude Opus 5.5 (high effort)

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