DIFFERENTIAL EQUATIONS — Maths STD 12 Science — Question

We have,

$\text{y}=4\sin3\text{x}\ ...(1)$

Differentiating both sides of equation (1) with respect to 3, we get

$\frac{\text{dy}}{\text{dx}}=12\cos3\text{x}\ ...(2)$

Differentiating both sides of equation (2) with respect to 3, we get

$\frac{\text{d}^2\text{y}}{\text{dx}^2}=-36\sin3\text{x}$

$\Rightarrow\frac{\text{d}^2\text{y}}{\text{dx}^2}=-9(4\sin3\text{x})$

$\Rightarrow\frac{\text{d}^2\text{y}}{\text{dx}^2}=-9\text{y}$

$\Rightarrow\frac{\text{d}^2\text{y}}{\text{dx}^2}+9\text{y}=0$

Hence, the given function is the solution to the given differential equation.