Answer:
1. X > 1
Step-by-step explanation:
We know because . That's why
.
We can now subtract 1 in both sides of the inequality:
.
Factoring as a difference of cubes, we get:
.
Thus, we have two factors whose multiplication is positive. Then, both are positive or both are negative. The second case is impossible, because can never be positive. The reason is the following:
witch is always positive because is a sum of squares, and the squares are always positive.
We conclude that both and have to be positive, and then implies