0606 P23 - Jun 2021 - Q4 - 4 marks
8000
Variables \(x\) and \(y\) are such that
\(y=\frac{\sin x}{\cos x}.\)
Use differentiation to find the approximate change in \(y\) as \(x\) increases from \(-\frac{\pi}{4}\) to \(h-\frac{\pi}{4}\), where \(h\) is small.
