The strength of a signal SSS detected by a proximity sensor is modeled by the function
S=13.5−∣1.5p−6∣ S = 13.5 - |1.5p - 6| S=13.5−∣1.5p−6∣where ppp is the position of an object on a linear track. Sketch the graph of SSS against ppp, marking the coordinates of the vertex and any points where the graph intersects the coordinate axes.
The sensor triggers an alarm when the signal strength is strictly less than 9 units. Solve the inequality
13.5−∣1.5p−6∣<9 13.5 - |1.5p - 6| < 9 13.5−∣1.5p−6∣<9to find the range of values for ppp for which the alarm is active.