So I had a test and this was the only exercise I miss points at and I can not understand why, I did everything according to my class notes. A particle moves according to the following equation: x=( −0.00521 cm/s^4 ) t^4 +( 0.0895 cm/s^3 ) t^3 + ( 0.335 cm/s^2 ) t^2−( 1.881 cm/s ) t−1.237 cm a) What is the initial position of the particle? x0=-1.237 cm (correct) b) What is the initial velocity of the particle? v0= -18.881 cm/s (correct) c) What is the particle's initial acceleration? a0= 0.355 cm/s^2 (incorrect), don't we just take the values from the formula given for x0, v0 and a0? That is what I have on my notes. d) What is the particle's initial jerk? j0=0 (incorrect) isn't the j0 always 0 regardless of the equation? e) What is the particle's position at t = 2.67 seconds? dx/dt=(-0.02084 cm/s^4) t^3 + (0.20685 cm/s^3) t^2 + (0.67 cm/s^2) t - 1.881 cm/s (correct) x2.67= 1.4 cm (incorrect) I plug 2.67 for t and got 1.425337693, did I get it wrong because I rounded? f) What is the particle's velocity at t = 2.67 seconds? dx/dt= (-0.06252 cm/s^4) t^2 + (0.537 cm/s^3) t + 0.67 cm/s^2 (correct) v2.67= 1.7 cm/s (incorrect) I plug 2.67 for t and got 1.678091172, did i get it wrong because I rounded? g) What is the particle's acceleration at t = 2.67 seconds? da/dt= (-0.12504 cm/s^4) t + 0.537 cm/s^3 (correct) a2.67= 0.2 cm/s^2 (incorrect) I plug 2.67 for t and got 0.2031432. No way I would get counted wrong because of rounding here. What am i doing wrong? h) What is the particle's jerk at t = 2.67 seconds? j2.67= -0.12504 cm/s^4 (incorrect) that the only value left if I take the derivative, still got it wrong. Sorry for the long post, thanks in advance.