Gujarat Board GSEB Textbook Solutions Class 12 Maths Chapter 9 Differential Equations Ex 9.1 Textbook Questions and Answers.

Gujarat Board Textbook Solutions Class 12 Maths Chapter 9 Differential Equations Ex 9.1

Determine orders and degrees (if defined) of the differential equations given ¡n questions 1 to 10:
Question 1.
(frac{d^{4} y}{d x^{4}}) + sin(y”’) = 0
Solution:
∴ Order : 4
∴ Degree : It is not a polynomial in derivatives.

Question 2.
y’ + 5y = 0
Solution:
∴ Order : 1
∴ Degree : 1

Question 3.
((frac{ds}{dt}))⁴ + 3((frac{d^{2} s}{d t^{2}})) = 0
Solution:
∴ Order : 2
∴ Degree : 1

Question 4.
((frac{d^{2} y}{d x^{2}}))² + cos ((frac{dy}{dx})) = 0
Solution:
∴ Order : 2
∴ Degree : Not a polynomial in derivatives.

Question 5.
((frac{d^{2} y}{d x^{2}})) = cos 3x + sin 3x
Solution:
∴ Order : 2
∴ Degree : 1

Question 6.
(y”’)² + (y”)³ + (y’)⁴ + y⁵ = 0
Solution:
∴ order : 3
∴ Degree : 2

Question 7.
y”’ + 2y” + y’ = 0
Solution:
∴ Order : 3
∴ Degree : 1

Question 8.
y’ + y = e^x
Solution:
∴ Order : 1
∴ Degree : 1

Question 9.
y” + (y’)² + 2y = 0
Solution:
∴ Order : 2
∴ Degree : 1

Question 10.
y” + 2y’ + sin y = 0
Solution:
∴ Order : 2
∴ Degree : 1

Choose the correct answers in the following questions 11 and 12:

Question 11.
The degree of differential equation
(left(frac{d^{2} y}{d x^{2}}right))³ + ((frac{1}{2}))² + sin((frac{dy}{dx})) + 1 = 0 is
(A) 1
(B) 2
(C) 1
(D) not defined
Solution:
Part (D) is the correct answer, since equation contain sin ((frac{dy}{dx})), which does not form a polynomial in derivatives.

Question 12.
The order of differential equation 2x²(frac{d^{2} y}{d x^{2}}) – 3(frac{dy}{dx}) + y = 0 is
(A) 1
(B) 1
(C) 0
(D) not defined
Solution:
Order of given differential equation is 2.
∴ Part (A) is the correct answer.