Question

The differential equation of all the lines in the xy-plane is

• A. $\frac { d y } { d x } - x = 0$
• B. $\frac { d ^ { 2 } y } { d x ^ { 2 } } - x \frac { d y } { d x } = 0$
• C. $\frac { d ^ { 2 } y } { d x ^ { 2 } } = 0$
• D. $\frac { d ^ { 2 } y } { d x ^ { 2 } } + x = 0$

Answer 1

Answer: (C)

$\frac { d ^ { 2 } y } { d x ^ { 2 } } = 0$

Answer 2

The equation of all the lines in xy-plane is given by $y = m x + c$

Differentiate it twice w.r.t. x, we get $\frac { d ^ { 2 } y } { d x ^ { 2 } } = 0$ .