[填空题]
$\text { Let } f(x)=x^{3}+2 x^{2}+k x-3 \text {. Part of the graph of } f \text { is shown in the following diagram. }$
The graph of f crosses the y -axis at the point Q . The line L is tangent to the graph of f at Q .
1. Find the coordinates of Q . y =
2. a. Find $f^{\prime}(x)$ . f'(x) =
b. Hence find the equation of L in terms of k . y =
The graph of f has a local maximum at the point P . The line L passes through P .
3 . Find the value of k .
