A particle moves so that it is at $\left( 3 \sin \frac{t}{4}, 3 \cos \frac{t}{4} \right)$ at time $t.$  Find the speed of the particle, measured in unit of distance per unit of time.
<|im_start|>system
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<|im_start|>user
A particle moves so that it is at $\left( 3 \sin \frac{t}{4}, 3 \cos \frac{t}{4} \right)$ at time $t.$  Find the speed of the particle, measured in unit of distance per unit of time.
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<|im_start|>assistant

user
\frac{3}{4}
A particle moves so that it is at $\left( 3 \sin \frac{t}{4}, 3 \cos \frac{t}{4} \right)$ at time $t.$  Find the speed of the particle, measured in unit of distance per unit of time.
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