Gregory plans to purchase a video game player. he has $500 in his savings account and plans to save $20 per week from his allowance until he has enough money to buy the player.
he needs to figure out how long it will take. what type of function should he use to model this problem? justify your answer mathematically.

The position of a moving particle is given by the position function: f(t)=-9t-t^2-0.2t^3+0.1t^4 a. at what time does the particle reverse direction? b. when is the displacement positive? (round one decimal place and answer in interval notation) c. when is the displacement negative? (round one decimal place and answer in interval notation) d. when is the particle’s acceleration positive? (round one decimal place and answer in interval notation) e. when is the particle’s acceleration negative? (round one decimal place and answer in interval notation)

If the value of cos330°is√3/2 then find cos 165°.

On the first of each month sasha runs a 5k race she keeps track of her times to track her progress her time in minutes is recorded in the table