Balbharati Maharashtra State BoardStd 12 Commerce Statistics Part 1 Digest PdfChapter 8 Differential Equation and Applications Ex 8.1 Questions and Answers.
Maharashtra State Board 12th Commerce Maths Solutions Chapter 8 Differential Equation and Applications Ex 8.1
(ii)
Solution:
The given D.E. is
This D.E. has highest order derivative with power 2.
∴ the given D.E. is of order 2 and degree 2.
(iii)
Solution:
The given D.E. is
This D.E. has highest order derivative with power 1.
∴ the given D.E. is of order 4 and degree 1.
(iv) (y'”)2+ 2(y”)2+ 6y’ + 7y = 0
Solution:
The given D.E. is (y”‘)2+ 2(y”)2+ 6y’ + 7y = 0
This can be written as
This D.E. has highest order derivative with power 2.
∴ the given D.E. is of order 3 and degree 2.
(v)
Solution:
The given D.E. is
On squaring both sides, we get
∴
This D.E. has highest order derivative with power 5.
∴ the given D.E. is of order 1 and degree 5.
(vi)
Solution:
The given D.E. is
This D.E. has highest order derivative with power 1.
∴ the given D.E. is of order 2 and degree 1.
(vii)
Solution:
The given D.E. is
i.e.,
This D.E. has highest order derivative with power 1.
∴ the given D.E. is of order 3 and degree 1.


(ii) y = xn
Differentiating twice w.r.t. x, we get
This shows that y = xnis a solution of the D.E.

(iii) y = ex
Differentiating w.r.t. x, we get
= ex= y
Hence, y = ex is a solution of the D.E. = y.
(iv) y = 1 – log x
Differentiating w.r.t. x, we get
Hence, y = 1 – log x is a solution of the D.E.

(v) y = aex+ be-x
Differentiating w.r.t. x, we get
= a(ex) + b(-e-x) = aex– be-x
Differentiating again w.r.t. x, we get
= a(ex) – b(-e-x)
= aex+ be-x
= y
Hence, y = aex+ be-xis a solution of the D.E. = y.
(vi) ax2+ by2= 5
Differentiating w.r.t. x, we get
Hence, ax2+ by2= 5 is a solution of the D.E.
