11: The conditions give (in the same order):
- This condition is true for
x ≥ −2.
- This condition is true for
x ≤ 10.
- Since square roots can never be negative, this condition is equivalent
to the condition that the sum of roots is not zero. A sum of two
non-negative numbers can be zero only if both are equal to zero. It is easy
to check that the two roots can never be simultaneously zero, so the third
condition is always true.
Now intersect these conditions.
Answer