7 The diagram shows a curve which starts from the point \(A\) with coordinates ( 0,2 ). The curve is such that, at every point \(P\) on the curve,
$$\frac { \mathrm { d } y } { \mathrm {~d} x } = \frac { 1 } { 2 } s$$
where \(s\) is the length of the \(\operatorname { arc } A P\).
\includegraphics[max width=\textwidth, alt={}, center]{587aac5c-fbc2-41d2-b1b3-16f3f7851d9d-4_399_764_1324_605}
- Show that
$$\frac { \mathrm { d } s } { \mathrm {~d} x } = \frac { 1 } { 2 } \sqrt { 4 + s ^ { 2 } }$$
(3 marks)
- Hence show that
$$s = 2 \sinh \frac { x } { 2 }$$
- Hence find the cartesian equation of the curve.
- Show that
$$y ^ { 2 } = 4 + s ^ { 2 }$$