Can anybody tell me what the equation for this graphs is please

Period is the time it takes for one “cycle” to complete. in the parent sine function, period is 2*pi since sin(0) = 0, sin(pi/2) = 1, sin(pi) = 0, sin(3pi/2) = -1, and sin(2pi) = 0. at that point, the sequence repeats itself. i’m not sure if your graph is similar to the sine function since you didn’t provide a picture, but you can find the period by looking at a graph.

It is a trinomial with a degree of 2 i believe

3you can not round up to four, as there was not a full payment for the fourth night, so uou would round down to 3