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AP® Calculus AB-BC

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Moderate

Increasing Speed

APCALC-YE24KU

A particle moves along the y-axis according to the equation $y(t)=-t^3+3t^2-6$ for $0 \le t \le 9$. During which time interval(s) is the speed of the particle increasing?

I. $(0, 1)$
II. $(0, 2)$
III. $(2, 9]$

A

I. only

B

II. only

C

III. only

D

I. and III. only