Question

The order and degree of the differential equation

$\sqrt { \frac { d y } { d x } } - 4 \frac { d y } { d x } - 7 x = 0$are

• A. 1 and 1/2
• B. 2 and 1
• C. 1 and 1
• D. 1 and 2

Answer 1

Answer: (D)

1 and 2

Answer 2

Given equation $\sqrt { \frac { d y } { d x } } - 4 \cdot \frac { d y } { d x } - 7 x = 0$

⇒ $\frac { d y } { d x } = 16 \left( \frac { d y } { d x } \right) ^ { 2 } + 49 x ^ { 2 } + 56 x \frac { d y } { d x }$

Obviously, it is first order and second degree differential equation

$\sqrt { \frac { d y } { d x } } - 4 \cdot \frac { d y } { d x } - 7 x = 0$

⇒ $\frac { d y } { d x } = 16 \left( \frac { d y } { d x } \right) ^ { 2 } + 49 x ^ { 2 } + 56 x \frac { d y } { d x }$