It's a rational number. 9 is a perfect square. What you have asked is written as -sqrt(9), which can be written as -sqrt(3*3) which is - 3. That's perfectly OK. What would not be OK is something like -sqrt(10) which is irrational because it cannot be represented as a fraction or a whole number or a repeating decimal or a decimal that terminates.
the answer would be a or b. Turn on verified mode for professionals to answer)
