Which are the roots of the quadratic function f(b) = b2 – 75?

[SunnyCBSE]

Which are the roots of the quadratic function f(b) = b2 – 75? check all that apply.

1. b = 5 square root of 3
2. b = -5 square root of 3
3. b = 3 square root of 5
4. b = -3 square root of 5
5. b = 25 square root of 3
6. b = -25 square root of 3