Question regarding periodic function w/ period of 15

[fred2028]

Hi, I have a homework review question that I do not know how to do.

5. A periodic function f has a period of 15. If f(5) = 13 and f(40) = -5, determine:

a) f(110)
b) f(200)
c) f(-80)

I tried finding the equation, but not enough variables were given.

 

[skeeter]

hint: if a function has a period of 15, then

... = f(-25) = f(-10) = f(5) = f(20) = f(35) = ...

and

... = f(10) = f(25) = f(40) = f(55) = f(70) = ...

 

[fred2028]

hint: if a function has a period of 15, then

... = f(-25) = f(-10) = f(5) = f(20) = f(35) = ...

and

... = f(10) = f(25) = f(40) = f(55) = f(70) = ...

Oh I get it. Thanks