Odgovor:
Hitrost je # = (sqrt6-sqrt2) /2=0.52#
Pojasnilo:
Hitrost je derivat položaja
#p (t) = sin (2t-pi / 4) + 2 #
#v (t) = p '(t) = 2cos (2t-pi / 4) #
Kdaj # t = pi / 3 #
#v (pi / 3) = 2cos (2 * pi / 3-pi / 4) #
# = 2co (2 / 3pi-1 / 4pi) #
# = 2 * (cos (2 / 3pi) * cos (pi / 4) + sin (2 / 3pi) * sin (1 / 4pi)) #
# = 2 * (- 1/2 * sqrt2 / 2 + sqrt3 / 2 * sqrt2 / 2) #
# = (sqrt6-sqrt2) /2=0.52#