So I was given the equation f(t)= cos(pi(t) / 6) and was told to find the velocity equation which was the first derivative,

V(t)= -(pi/6) [sin(pi(t)/6)]. The part I'm having trouble with is finding the velocity after 1 second. I plugged in 1 into the velocity equation and got an answer but it keeps saying it's wrong and I have no idea what I'm doing wrong.

Ruublrr Mar 9, 2019

#1**+3 **

\(f(t) = \cos\left(\dfrac{\pi t}{6}\right)\\ \dfrac{df}{dt}(t) = -\sin\left(\dfrac{\pi t}{6}\right)\cdot \dfrac \pi 6\\ \dfrac{df}{dt}(1) = -\sin\left(\dfrac{\pi}{6}\right)\cdot \dfrac \pi 6 = -\dfrac 1 2 \dfrac \pi 6 = -\dfrac{\pi}{12}\)

What did you get?

Rom Mar 9, 2019