Mathematics: the following statements are correct: 1. X = 4 is the solution set of inequality X-1 > 2. 2. The solution of inequality - 2x > 4 is X

Mathematics: the following statements are correct: 1. X = 4 is the solution set of inequality X-1 > 2. 2. The solution of inequality - 2x > 4 is X

1. X = 4 is the solution set of inequality X-1 > 2
The solution set of∵ inequality is: x > 3
"X = 4 is the solution set of inequality X-1 > 2" is wrong, x = 4 is only a solution of inequality
2. The solution set of inequality - 2x > 4 is x0: x > 1 / 2
"X > 1 / 2 is the solution set of inequality 2x-1 > 0" is correct

It is known that the set P is equal to {x | ax's Square plus 2x plus 1 equals 0, X belongs to R}. If the set P is an empty set, what is the value range of a

∵ set P is empty, ∵ ax & # 178; + 2x + 1 ≠ 0
That is △ 2 & # 178; - 4A > 0
The solution is a < 1
If P is an empty set, then the value range of a is (- ∞, 1)

If the square plus 2x plus 1 of the equation AX equals 0 and has negative roots, then the value set of a is?

Is the equation like this? Ax & # 178; + 2x + 1 = 0 when a = 0, the equation AX & # 178; + 2x + 1 = 0 can be transformed into the equation 2x + 1 = 0, and the equation has a negative root. When a ≠ 0, if the quadratic equation ax & # 178; + 2x + 1 = 0 has a root, then △ = 4-4a ≥ 0, that is, a ≤ 1. If the equation AX & # 178; + 2x + 1 = 0 has no negative root, then X1 + x2 = - 2 / a ≥ 0, X1 &

It is known that the set a is equal to the third power of the brace x | ax + the square of X - x is equal to 0. If the set a is a single element set, the value range of a ～

ax^3+x^2-x=x(ax^2+x-1)=0
The single element set means that the above equation has only one solution
The above equation must have a solution of x = 0, so (AX ^ 2 + x-1) = 0 must have no solution
When a = 0, x = 1
When a ≠ 0, if there is no solution, the discriminant is less than 0
The solution is a