### Instruction: The greatest integer function of $x$ is expressed as $[x]$ and is defined to be the greatest integer less than or equal to $x$. Find $[\pi - 4]$.### Response: So what's the greatest integer less than or equal to $\pi$?
That would be 3.
Ok and what's the greatest integer less than or equal to 4?
That's 4.
Ok so the greatest integer less than or equal to $\pi-4$ is $3-4=-1$.
Oh wait, are you sure that's right?
Yes, why?
Well, the greatest integer less than or equal to $\pi$ is 3, but the greatest integer less than or equal to 4 is not 4, it's 3.