Noelle has 198 coins, all nickels and dimes. noelle has 20 more nickels than dimes. how many of each coin does noelle have?

109 nickels and 89 dimes

Steps:
198 coins in total and the amount of nickels are 20 more than dimes. (n for the amount of nickels, d for the amount of dimes):

n = 20 + d
n + d = 198

Take the first equation and make it into:
n - d = 20

Now let’s add both equations together:
n + d + n - d = 218
2n = 218
n = 109

109 - 20 = d
d = 89

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.