The position function of a particle in rectilinear motion is given by s(t) = 2t^3 - 21t^2 + 60t + 3 for t ≥ 0. find the position and acceleration of the particle at the instant when the particle reverses direction. include units in your answer.
so i've already gotten the first derivative(6t^2-42t+60) and set it to 0. this resulted in t=5 and t=2. i then took the second derivative(12t-42) and plugged in t for acceleration. where do i go from here?

Idont understand math at all! : o( use this scenario to answer the remaining questions: brenton purchased a new bedroom set for $4,500.00. he lives in arizona and pays a 8.75% sales tax. if he made a 50% down payment and financed the rest, what amount did he finance? what is the total sales tax brenton will pay? enter your answer in currency format, round to the nearest cent. what was brenton's total amount financed? enter your answer in currency format, round to the nearest cent.

Create a data set with 8 points in it that has a mean of approximately 10 and a standard deviation of approximately 1.

The cost of using a service is $0.25 per min. what equation correctly represents the total cost c, in dollars, for d days of use?