I'm kind of clueless, apart from its a min/max thing. The question is as follows:
The water levels in a dock follow (approximately) a 12-hour cycle, and are modeled by the equation $D = A+ B\sin30t$, where $D$ metres is the depth of water in the dock, $A$ and $B$ are positive constants, and $t$ is the time in hours after 8 a.m.
Given that the greatest and least depths of water in the dock are 7.80m and 2.20m respectively, find the value of A and the value of B
Find the depth of water in the dock at noon, giving your answer correct to the nearest cm.
Thanks in advance.