Question

o vetor velocidade de v=(-2 sen t)i+(2 cos t)j quando t=pi/2

Answer 1

v = (-2sent)i + (2cost)j
v = -2sen(pi)i/2 + 2cos(pi)/2
v = -2sen90i + 2cos90j
v = -2(1)i + 2(0)j
v = -2i