(d-15)^2

t= + 20

300

the average temperature around the tropic of cancer for a particular day in january can be modeled using the equation above, where t is the temperature in degrees celsius and d is the number of days after january 1 (on january 1, d=0). according to this model, what is the lowest average temperature, in degrees celsius, for a day in january, which has 31 days?

The expression for temperature is already in vertex form: T=a(d−d subscript 0)^2+T subscript 0. The vertex of this quadratic function occurs at (15,20).

with such great emphasis put on the act and sat exams—the studying, the review sessions, taking the test, retaking the test, scholarships dependent on scores, etc.—many think the scores are the be all end all of college applications. if you have a high score, you can get into any college you want. if you have a low score, you’re doomed.