Question

How do you graph `y= sqrt (x-4)`?

Answer 1

First, we need to find the domain of this equation

There are some rules about square roots, but this is the one we care about today:
No square roots of a negative number

So, we need to find the value of `x` that gives us a negative number, or one that is less that `0`.
`x-4=0`
add `4` on both sides
`x=4`

So, `x=4` is the smallest value of `x` we can square root

Our domain is `[4, oo]`

Other than the shift to the right, our graph should look the same as the normal `sqrt(x)`:
graph{y=sqrt(x-4)}