Increasing and decreasing Problem set B Answers

\(x>-2\)

1. (a) \(0<x<3\)
2. (b) \(x<0\) or \(x>3\)

1. (a) \(180<x<360\)
2. (b) x = 0, x = 180 and x = 360

1. (a) -2
2. (b) x = 3

1. (a) \(0\le t<2\) or \(6<t\le 8\)
2. (b) 0. The depth is neither rising nor falling for an instant (the tank is at its fullest)

Gradient zero at x = 0 (local minimum) and x = 4 (local maximum). The graph falls, rises, then falls: the shape of a cubic with a negative x³ term.

1. (a) \(-3<x<0\) or \(x>3\)
2. (b) x = −3, x = 0, x = 3