What is f union h and f intersect h?

F ∪ H = (-∞, ∞)

F ∩ H = [4,7)

Step-by-step explanation:

First it's a good idea to write both F and H in interval notation.  F is [4, ∞) because the lowest point is 4, and it can equal 4, so the bracket, and then the upper limit is infinity, which always has a parenthesis.

H is (-∞, 7) because it's lowest limit is negative infinity and upper limit is 7, but it cannot equal 7 so it has a parenthesis as well.

Now we find the union and intersection.  Union is everything in both.  H starts at negative infinty and goes up to 7, but F starts at 4 and goes to infinity, so F includes the end of H so it's all a continuous from negative infinity to infinity, both having parenthesis.

The intersection is just what the two sets share.  F has the same elements as H does  from 4 to 7, not including 7, let me know if you need help catching this, or any part really.