# Thread: Function of a Graph

1. ## Function of a Graph

I need to find the formula of the function graphed below. The closest I've gotten is 5sin(-.78x)+5, but it doesn't quite match.

2. ## Re: Function of a Graph

The period is 8.

So, $f(x) = 5-5\sin x$ has period $2\pi$. To change it to $8$, you need to multiply $x$ by $\dfrac{2\pi}{8} = \dfrac{\pi}{4}$.

$f(x) = 5-5\sin\left( \dfrac{\pi}{4} x \right)$