What does the point (15,20) mean in this situation?

Which of the following is the true for f(x) = 5cos

Ineed to know the ordered pairs for this equation i need the answer quick because it’s a timed test

If (x + 8) is a factor of f(x), which of the following must be true? both x = –8 and x = 8 are roots of f(x). neither x = –8 nor x = 8 is a root of f(x). f(–8) = 0 f(8) = 0