Question Details

A differential equation is given as The solution of the differential equation in terms of arbitrary constants C1 and C2 is bhjvhhgghvhbjj

Options

A

B

C

D

Correct Answer :

Solution :

The correct option is:
y = C1 x2 + C2 x + 2

Analysis of the Question:
From the provided images, the differential equation to solve is:
x2 d2 y d x2 2 x d y d x + 2 y = 4

This equation is a second-order Cauchy-Euler differential equation (also known as a homogeneous linear differential equation).

Step 1: Substitution to constant coefficient form
To solve this, we introduce a new independent variable z using the substitution:
x = ez or z = ln ( x )

Using the chain rule, we can relate the derivatives with respect to x to derivatives with respect to z. Let D=ddz:
x d y d x = D y
And for the second derivative:
x2 d2 y d x2 = D ( D 1 ) y

Substituting these expressions into our original differential equation gives:
[ D ( D 1 ) 2 D + 2 ] y = 4
Expanding and simplifying the operator:
( D2 D 2 D + 2 ) y = 4
( D2 3 D + 2 ) y = 4

Step 2: Finding the Complementary Function (CF)
To find the complementary function yc, we solve the homogeneous equation:
( D2 3 D + 2 ) y = 0
The corresponding auxiliary algebraic equation is:
m2 3 m + 2 = 0
Factoring the quadratic expression:
( m 1 ) ( m 2 ) = 0
Which yields the real and distinct roots:
m1 = 1 , m2 = 2

Thus, the solution of the homogeneous equation in terms of z is:
yc = C1 e2z + C2 ez
Substituting ez=x back into the equation:
yc = C1 x2 + C2 x

Step 3: Finding the Particular Integral (PI)
The particular integral yp is calculated for the non-homogeneous term:
yp = 1 D2 3 D + 2 ( 4 )
We can write the constant 4 as 4e0z. According to the rules for finding the PI of an exponential term eaz, we substitute D=a=0:
yp = 4 02 3 ( 0 ) + 2 = 4 2 = 2

Step 4: Writing the General Solution
The complete general solution is the sum of the complementary function and the particular integral:
y = yc + yp
y = C1 x2 + C2 x + 2

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