College Algebra!

Checkpoint Quiz 2.1

Name:

1. The US Unemployment Rate was 5.0% in January 2008 and 7.7% in January 2009.1

(a) Find a linear function which fits these data using the number of years since January 2008, t, as the independent variable and the unemployment rate, U , as the dependent variable.

(b) Find a reasonable applied domain for the model you found in (a).

(c) Use this model to predict the unemployment rate in January 2010.

NOTE: The actual unemployment rate was 9.7%.

2. The height of a frog off the ground, h (in feet) t seconds after it jumps in the air is given by

h(t) = −16t2 + 32t, 0 ≤ t ≤ 2.

Find and interpret the average rate of change of h over the interval [1, 2].

1Source: http://www.bls.gov/cps/