Match List – I with List – II.
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LIST I |
LIST II |
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A. $\frac{d^2 y}{d x^2}=\left(\frac{d y}{d x}\right)^{\frac{3}{2}}$ |
I. order + degree = 2 |
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B. $2\left(\frac{d^3 y}{d x^3}\right)^2+3\left(\frac{d^2 y}{d x^2}\right)+y\left(\frac{d y}{d x}\right)^2=e^x$ |
II. order + degree = 3 |
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C. $\frac{d y}{d x}+\frac{1}{d y / d x}=3$ |
III. order + degree = 4 |
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D. $\frac{d y}{d x}+x^2=5$ |
IV. order + degree = 5 |
Choose the correct answer from the options given below:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → A-III, B-IV, C-II, D-I
A. $\frac{d^2 y}{d x^2}=\left(\frac{d y}{d x}\right)^{\frac{3}{2}}$
To find the degree, we must square both sides to remove the fractional exponent:
$\left(\frac{d^2 y}{d x^2}\right)^2 = \left(\frac{d y}{d x}\right)^3$
- Order: 2
- Degree: 2
- Sum: $2 + 2 = 4$ (Matches III)
B. $2\left(\frac{d^3 y}{d x^3}\right)^2+3\left(\frac{d^2 y}{d x^2}\right)+y\left(\frac{d y}{d x}\right)^2=e^x$
The highest derivative is the third derivative.
- Order: 3
- Degree: 2
- Sum: $3 + 2 = 5$ (Matches IV)
C. $\frac{d y}{d x}+\frac{1}{d y / d x}=3$
Multiply the entire equation by $\frac{dy}{dx}$ to clear the fraction:
$\left(\frac{d y}{d x}\right)^2 + 1 = 3\left(\frac{d y}{d x}\right)$
- Order: 1
- Degree: 2
- Sum: $1 + 2 = 3$ (Matches II)
D. $\frac{d y}{d x}+x^2=5$
This is a standard first-order equation.
- Order: 1
- Degree: 1
- Sum: $1 + 1 = 2$ (Matches I)