A rock is tossed from a platform and follows a parabolic path through the air. The height of the rock in meters is given by h(t) = -5t^2 + 12t + 14, where t is measured in seconds. b. How long is the rock in the air?
c. For what times is the height of the rock greater than 17 m?
d. How long is the rock above a height of 17 m?

Mr. brettler is hanging up a 5-foot tall rectangular welcome sign in the gym. he has drawn a sketch on a coordinate grid. he has the lower vertices of the sign at (9, –3) and (–6, –3). where would the upper vertices be on the grid?

Christine wong has asked dave and mike to her move into a new apartment on sunday morning. she has asked them both, in case one of them does not show up. from past experience, christine knows that there is a 40% chance that dave will not show up and a 30% chance that mik a. what is the probability that both dave and mike will show up? (round your answer to 2 decimal places.) b. what is the probability that at least one of them will show up? c. what is the probability that neither dave nor mike will show up? (round your answer to 2 decimal places.)e will not show up. dave and mike do not know each other and their decisions can be assumed to be independent.

Tan198=asin164=? how to solve this? ?