Compute r''(t).
-r(t) = ( 2 cos t)i + ( 4 sin t)j
A) r''(t) = (-2 cos t)i + (-4 sin t)j
B) r''(t) = ( 2 cos t)i + ( 4 sin t)j
C) r''(t) = ( 2 sin t)i + ( 4 cos t)j
D) r''(t) = (-2 sin t)i + (-4 cos t)j

Question

Quizplus · Accepted Answer

The second derivative of $r(t) = (2 \cos t)i + (4 \sin t)j$ with respect to $t$ is $r''(t) = (-2 \cos t)i + (-4 \sin t)j$, because the second derivative of $\cos t$ is $-\cos t$ and the second derivative of $\sin t$ is $-\sin t$.

Compute R''(t). -R(t) = ( 2 Cos T)i + ( 4 Sin