Marcus is buying his first tank of gasoline since he got his driver's license. Where he lives, gasoline is selling for
between $1.20 and $1.40 per gallon. If he has $10.50 to spend on gas,
how many gallons can he buy?

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.