Two simple high school inequality questions ~ speed 1. Proof: the square of a + the square of B ≥ AB + A + B-1 2. Verification: 2 (radical (n + 1) - 1) < 1 + 1 / (radical 2) + 1 / (radical 3) + +1 / (radical n) < 2 (radical n)

Two simple high school inequality questions ~ speed 1. Proof: the square of a + the square of B ≥ AB + A + B-1 2. Verification: 2 (radical (n + 1) - 1) < 1 + 1 / (radical 2) + 1 / (radical 3) + +1 / (radical n) < 2 (radical n)

Question 1: the square of a + the square of B - 2Ab is greater than or equal to 0
The square of a - 2A + 1 is greater than or equal to 0
The square of B - 2b + 1 is greater than or equal to 0
Formula 1, formula 2 and formula 3 are added
2 times the square of a + 2 times the square of B - 2ab-2a-2b-2 is greater than or equal to 0
Then we prove the inequality by two