If $$A = \{2, 4, 6, \}$$, $$B = \{5, 7, 1, 9\}$$.
Let R be the relation ‘is less than’ from A to B. Find Domain (R) and Range (R).
| Subject | Number of students |
| Mathematics | $$100$$ |
| Physics | $$70$$ |
| Chemistry | $$46$$ |
| Mathematics and Physics | $$30$$ |
| Mathematics and Chemistry | $$28$$ |
| Physics and Chemistry | $$23$$ |
| Mathematics, Physics and Chemistry | $$18$$ |
Find range & domain of following $$\sqrt {4 - {x^2}} $$