Explanation:
\(\frac{dy}{dx} = \frac{sin(a+y) cosy - siny cos(a+y)}{sin^2(a+y)}\)
\(x = \frac{siny}{sin(a+y)}\)
On differentiating w.r.t. y, we get
\(=\frac{sin(a+y-y)}{sin^2(a+y)}\)
\(\Rightarrow \frac{dy}{dx}=\frac{sin^2(a+y)}{sina}\)
The solution of $(D^2 + 16)$ $y = cos4x$ is