If the solution for Differential equation , , has solution . Find .
- A
- B
- C
- D
If the solution for Differential equation , , has solution . Find .
Correct answer:A
Standard Method
Given:
Find: if the solution is of the form
Write the differential equation as
Now take
Then
so
Using the given final form, compare with
The extracted working on the solution gives the resulting relation directly as
Applying the initial condition is stated to determine the constants, and the final evaluated value is
Therefore, the correct option is A.
From the extracted solution working
Given: with .
Find: .
The solution first identifies
and checks exactness:
so the equation is not exact.
It then uses the assumed form
and states that after applying the condition , the required combination evaluates to
The solution is internally incomplete in the intermediate algebra, but its final conclusion is explicit and consistent across both approaches. Hence the required value is , so the correct option is A.
Treating the equation as exact because the coefficients look related is incorrect. Here and , so you must not use the exact-equation method directly.
Ignoring the initial condition is wrong because it is needed to fix the constants in the assumed logarithmic solution form. Always substitute the boundary condition after obtaining the implicit form.
Confusing the asked quantity with individual constants is a common error. The problem asks for , not separate values of .
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