1. When x > 1 is simplification ------------------- Square of (x + 1 / x) - 4 2. The two adjacent sides of the parallelogram are 3 and 5. The length of the two line segments divided by an acute angle bisector is 3. It is known that the length of four sides of a trapezoid is 1, 2, 3 and 4 respectively, then the area of the trapezoid is

1. When x > 1 is simplification ------------------- Square of (x + 1 / x) - 4 2. The two adjacent sides of the parallelogram are 3 and 5. The length of the two line segments divided by an acute angle bisector is 3. It is known that the length of four sides of a trapezoid is 1, 2, 3 and 4 respectively, then the area of the trapezoid is

1. The original formula = √ [(x + 1 / x + 2) · (x + 1 / X-2)] = √ [(x ^ 2 + 1-2x) / X · (x ^ 2 + 1 + 2x) / x] = √ [(x-1) ^ 2 / X · (x + 1) ^ 2 / x] = √ [(x ^ 2-1) / x] ^ 2 = (x ^ 2-1) / x2