Balbharti12th Maharashtra State Board Maths Solutions BookPdf Chapter 6 Differential Equations Ex 6.2 Questions and Answers.
Maharashtra State Board 12th Maths Solutions Chapter 6 Differential Equations Ex 6.2
(ii) Ax2+ By2= 1
Solution:
Ax2+ By2= 1
Differentiating both sides w.r.t. x, we get
A × 2x + B × 2y = 0
∴ Ax + By = 0 ……..(1)
Differentiating again w.r.t. x, we get
Substituting the value of A in (1), we get
This is the required D.E.


Alternative Method:
Ax2+ By2= 1 ……..(1)
Differentiating both sides w.r.t. x, we get
A × 2x + B × 2y = 0
∴ Ax + By = 0 ……….(2)
Differentiating again w.r.t. x, we get,
The equations (1), (2) and (3) are consistent in A and B.
∴ determinant of their consistency is zero.
This is the required D.E.


(iii) y = A cos(log x) + B sin(log x)
Solution:
y = A cos(log x) + B sin (log x) ……. (1)
Differentiating w.r.t. x, we get

(iv) y2= (x + c)3
Solution:
y2= (x + c)3
Differentiating w.r.t. x, we get
This is the required D.E.

(v) y = Ae5x+ Be-5x
Solution:
y = Ae5x+ Be-5x……….(1)
Differentiating twice w.r.t. x, we get
This is the required D.E.

(vi) (y – a)2= 4(x – b)
Solution:
(y – a)2= 4(x – b)
Differentiating both sides w.r.t. x, we get
2(y – a). (y – a) = 4 (x – b)
∴ 2(y – a). ( – 0) = 4(1 – 0)
∴ 2(y – a) = 4
∴ (y – a) = 2 ……..(1)
Differentiating w.r.t. x, we get
This is the required D.E.

(vii) y = a +
Solution:
y = a +
Differentiating w.r.t. x, we get
Substituting the value of a in (1), we get
This is the required D.E.


(viii) y = c1e2x+ c2e5x
Solution:
y = c1e2x+ c2e5x………(1)
Differentiating twice w.r.t. x, we get
= c1e2x× 2 + c2e5x× 5
The equations (1), (2) and (3) are consistent in c1e2xand c2e5x
∴ determinant of their consistency is zero.
This is the required D.E.


Alternative Method:
y = c1e2x+ c2e5x
Dividing both sides by e5x, we get
This is the required D.E.

(ix) c1x3+ c2y2= 5.
Solution:
c1x3+ c2y2= 5 ……….(1)
Differentiating w.r.t. x, we get
Differentiating again w.r.t. x, we get
The equations (1), (2) and (3) in c1, c2are consistent.
∴ determinant of their consistency is zero.
This is the required D.E.



(x) y = e-2x(A cos x + B sin x)
Solution:
y = e-2x(A cos x + B sin x)
∴ e2x. y = A cos x + B sin x ………(1)
Differentiating w.r.t. x, we get
Differentiating again w.r.t. x, we get
This is the required D.E.












