1. ## Functions graph problem

So first here is the graph: http://i56.tinypic.com/b8muja.png

The question is:
The figure above shows a portion of a graph of the function f. If f(x+5)=f(x) for all values of x, then f(x)=0 for how many different values of x between 0 and 12?

the book says the answer is 9, but i do not know how i would get that answer?
So how would i get that answer? thanks

2. For starters, you have labeled the vertical axis "y". Does the book label the vertical axis as y? The vertical label should be f(x), because nowhere in this problem is a variable y referenced. I will assume you have labeled it as y out of habit...

So, f(x) = 0 when y = 0. How many times between 0 and 5 do you see the graph cross the x axis? Where it crosses is where f(x) = y = 0. We know that the graph repeats its pattern every 5 units of x, so how many times do you count it will cross between 0 and 12? The answer in the book is correct.

3. Thank you borophyll , oh and the book does label the vertical axis as y. Thank you very much!!!