Question

What is the derivative of `y= x/pi`?

Answer 1

For any constant `c`
if `y = cx`

then `(dy)/(dx) = c`

Given

`y=x/pi= (1/pi)x`

and while `1/pi` might look like a weird constant, that's all it really is;
so

`(dy)/(dx) = 1/pi`

Answer 2

It is `1/pi`

Don't let `pi` confuse you. (It's sneaky that way.)

`pi` is just a number. It's a little bigger than 3.

Speaking of which, what is the derivative of `y=x/3`? Well, since `x/3=1/3x` it's the same as the derivative of any other number times `x`. It's just the number.
The derivative of `x/3` is `1/3`

Back to the question at hand:

`y=x/pi` is the same as `y=1/pix`.

So the derivative is `y'=1/pi`

Note

It is possible to use the quotient rule for this kind of thing, but it's more involved and more tedious. (And also likely to result in error.)