Logical are functions used when looking for an entry or value in the spreadsheet. what is it?

In a compound condition, both conditions on either side of the logical operator and must be true for the overall condition to be true. a: true b: false

Are special combinations of keys that tell a computer to perform a command. keypads multi-keys combinations shortcuts

Suppose there is a relation r(a, b, c) with a b+-tree index with search keys (a, b).1. what is the worst-case cost of finding records satisfying 10 < a < 50 using this index, in terms of the number of records n1, retrieved and the height h of the tree? 2. what is the worst-case cost of finding records satisfying 10 < a < 50 and 5 < b < 10 using this index, in terms of the number of records n2 that satisfy this selection, as well as n1 and h defined above? 3. under what conditions on n1 and n2, would the index be an efficient way of finding records satisfying the condition from part (2)?