15
QuizMultiple Choice

Modeling with Periodic Functions — Quiz

Question 15 • Precalculus

The height, h , in feet of the tip of the minute hand of a wall clock as a function of time, t , in minutes can be modeled by the equation h is equal to 0 point 7 5 cosine open paren pi over 30 times open paren t minus 15 close paren close paren plus 8 Which number (from 1 to 12 ) is the minute hand pointing to at t is equal to 0 ?

Answer
A
12
B
3
C
9
D
6

Explanation

At t = 0, the equation gives h = 8, the clock’s center height, so the tip is level with the center and the hand points either to 3 or 9. As time increases from 0, the height increases: the cosine angle moves from −π/2, where cosine is 0, toward values with positive cosine. The tip is therefore moving upward, which means the minute hand points to 9, choice C.

AI-written and checked against the verified answer.

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