June 4, 2013 Name: Answer Key
1. The average surface temperature of the earth can be modeled by the linear function T=.02t+8.50, where T is temperature in °C and t represents years since 1900.
What do the slope and T-intercept represent in this model?
The slope, .02, represents the number of degrees Celsius that the average surface temperature of the earth increases each year.
The T-intercept, 8.50, is the average surface temperature in 1900
2. Express the function
Note: this is not only possible answer, but it is the only one that makes both f and g as simple as possible.
3. Find all solutions of the equation correct to 3 decimal places (use your calculator).
Either graph and find the intersections, or graph and find its zeroes. Either way you should get x=-.724 and x=1.221
(which can be verified by substituting x=1 and x=3 and confirming that the desired y’s are obtained)