Posted by **thisha** on Wednesday, October 11, 2006 at 3:23pm.

1. let A and B be sets. Show that

A U (B - A)=A U B

2. determine whether f is a function from Z to R if

a) f(n)= +n

b) 1/(n square -4)

For 1. B-A is the same as B intersect ~A (That's the complement of A)

So A U B = A U (B int ~A) = (A U B) int (A U ~A) A U ~A is the universal set.

For 2. a) f(n) is the absolute value function, so yes, it's a function.

For 2. b) 1/(n^2 - 4) f is not defined at +/- 2

## Answer this Question

## Related Questions

- DISCRETE MATHS - Determine whether the pair of sets is equal. {1, 1, 2, 2, 2, 6...
- MATH - Determine whether the situation calls for a discrete or continuous random...
- math - Determine whether the situation calls for a discrete or continuous random...
- math-please help! - Determine whether the situation calls for a discrete or ...
- Math - In each case, determine whether the situation calls for a discrete or ...
- Discrete Math - Let A={0,1,2,3,4}. Define a function f from A to A by f(n)=2n ...
- math - Use a Venn diagram to determine whether A > (B < C) 5 (A > B) &...
- MATH - Determine whether the pairs of sets are equal, equivalent, both, or ...
- discrete math - Fill in the blanks: For all sets A and B, if A is in the set of ...
- math(Discrete) - Determine whether the statement ∀x ∈ Z, ∃y, z...