Key features and models of graphs Problem set B Answers

y-intercept \((0,\,-7)\); zeros \(x=1\) and \(x=7\); vertex \((4,\,9)\); axis \(x=4\)

1. (a) \(y=-6\)
2. (b) \(y=1\)
3. (c) \(y=-5\)

1. (a) 243
2. (b) 2

Asymptotes \(x=-4\) and \(y=3\); x-intercept \((4,\,0)\); y-intercept \((0,\,-3)\)

1. (a) Exponential: a constant ratio
2. (b) Quadratic: it rises, then falls
3. (c) Linear: a fixed charge and a constant rate

1. (a) 17.8 m
2. (b) 41.1 m
3. (c) The javelin is released 1.8 m above the ground.

1. (a) 200 °C
2. (b) 21 °C
3. (c) 29.7 minutes

1. (a) \(a=288\)
2. (b) 4.5 units
3. (c) Very close to the transmitter the strength is very large; it is never infinite.

1. (a) Linear: \(y=3x+5\); at \(x=12\) the height is 41 cm
2. (b) Exponential: \(y=3\times3^x\); at \(x=6\) there are 2187 people

\(a=2\); x-intercept \((2.5,\,0)\); y-intercept \((0,\,-1.67)\)

\(k=2,\ a=3,\ c=-1\); \(y=161\)