23. Find the particular solution to the differential equation [tex] y^{\prime} x^2 = y [/tex] that passes through [tex] \left(1, \frac{2}{e}\right) [/tex], given that [tex] y = C e^{-1 / x} [/tex] is a general solution.



Answer :

To find the particular solution to the differential equation [tex]\( y' x^2 = y \)[/tex] that passes through the point [tex]\(\left(1, \frac{2}{e}\right)\)[/tex], we start with the given general solution [tex]\( y = C e^{-1 / x} \)[/tex].

1. Substitute the given point into the general solution:
The point given is [tex]\( (1, \frac{2}{e}) \)[/tex]. Here, [tex]\( x = 1 \)[/tex] and [tex]\( y = \frac{2}{e} \)[/tex]. Substitute these values into the general solution to determine the constant [tex]\( C \)[/tex].

[tex]\[ y = C e^{-1 / x} \][/tex]

Substituting [tex]\( x = 1 \)[/tex] and [tex]\( y = \frac{2}{e} \)[/tex]:

[tex]\[ \frac{2}{e} = C e^{-1 / 1} \][/tex]

2. Simplify the expression:
[tex]\[ \frac{2}{e} = C e^{-1} \][/tex]

Note that [tex]\( e^{-1} \)[/tex] is equivalent to [tex]\( \frac{1}{e} \)[/tex], so substitute that in:

[tex]\[ \frac{2}{e} = C \cdot \frac{1}{e} \][/tex]

3. Solve for the constant [tex]\( C \)[/tex]:
[tex]\[ \frac{2}{e} = \frac{C}{e} \][/tex]

Multiply both sides by [tex]\( e \)[/tex]:

[tex]\[ 2 = C \][/tex]

So, we find that [tex]\( C = 2 \)[/tex].

4. Write the particular solution:
Substitute [tex]\( C = 2 \)[/tex] back into the general solution [tex]\( y = C e^{-1 / x} \)[/tex]:

[tex]\[ y = 2 e^{-1 / x} \][/tex]

Therefore, the particular solution to the differential equation [tex]\( y' x^2 = y \)[/tex] that passes through the point [tex]\(\left(1, \frac{2}{e}\right)\)[/tex] is:

[tex]\[ y = 2 e^{-1 / x} \][/tex]