Ernesto and his family went to dinner, the tax is 6% of the price of the meal. ernesto leaves an 18% tip. with tax and tip the total cost is $72.39. write an equation that models this situation.

The equation would be something like this:
y=72.39+ .18x+.06x
then simplify
y=72.39+.24x

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.