Fig. 9 shows the curve \(y = xe^{-2x}\) together with the straight line \(y = mx\), where \(m\) is a constant, with \(0 < m < 1\). The curve and the line meet at O and P. The dashed line is the tangent at P.
\includegraphics{figure_9}
- Show that the \(x\)-coordinate of P is \(-\frac{1}{2}\ln m\). [3]
- Find, in terms of \(m\), the gradient of the tangent to the curve at P. [4]
You are given that OP and this tangent are equally inclined to the \(x\)-axis.
- Show that \(m = e^{-2}\), and find the exact coordinates of P. [4]
- Find the exact area of the shaded region between the line OP and the curve. [7]