A particle's position in centimeters is given by the expression x = 40 cos(45 t + 8), where t is given in seconds. angular frequency= 45 rad/sec period= .139 s amplitude= 40 cm Heres the part i cant get but seems so simple... where is the particle at t= .05 sec? what is its velocity? what is its accleration? what is the maximum speed attained by the particle? So what i figured on doing is just plugging .05 into my original equation x = 40 cos(45 t + 8) to solve for distance....where t= .05, distance= 39.36....which came out to be wrong for some reason...(all is in cm) then for the rest i just add a "-w" infront of the equation for velocity and a "-w^2" for acceleration and then solve when a=0, velocity has a max or min.. any ideas?