exact/inexact results like sqrt and integer roots

Question

R6RS 3.4 Implementation requirements reads

... Potentially inexact operations such as sqrt, when applied to exact arguments, should produce exact answers whenever possible (for example the square root of an exact 4 ought to be an exact 2).

(1) Does this mean that (* 0 2.2) must produce 0.0 but never 0 as result?

However, this is not required. ...

(2) Does this mean that (/ 4 2) may also produce 2.0 as result?

(3) And are there implementations that provide integer roots in this manner? How do I get the functionality of integer square roots in general? (Here is the index) (Please no recursive/iterative implementation)

Answer 1

R6RS has exact-integer-sqrt. It returns two values, the square root and the remainder. You can discard the second value if you want.

Implementations are allowed (but not required) to consider (* 0 x) (multiplying anything by an exact zero) to be exact zero for any x. See the R6RS description of the * procedure.