Consider the function g:

{(2, 7), (4, 9), (12, 19), (20, 27), (31, 38)}

what is g (12)?

Another way to ask this question: where the x-value of function g equals 12, what's the y-value?

remember that function notation is like so: f(x), g(x), h(x)... so the number in the parentheses is an x-value from the function.

look through your points and find the one that represents an x-value of 12. (12, 19) is the point, and 19 is your output--so, g(12) = 19.

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.