2. If the real number x ∈ {1, 2, the square of x} is known, then the real number x is equal to?
3. Counterevidence If x, y∈R is known and x+y is greater than 2, at least one of x and y is greater than 1.
4. the set a = {x │ x2-5x+6 = 0}, b = {x │ MX+ 1 = 0}, A∪B=A, which is a set composed of the values of real number m. ..
5. It is known that geometric series {BN} and sequence {{a n}} satisfy BN = 3an power, n∈N*,
(1) Judge what kind of series {{a n}} is and give the proof;
(2) if A8+A 13 = m, find b 1, b2, ..., b20?
6. It is known that u = {x │ x2-5/2x+ 1 ≥ 0}, a = {x │ x- 1 │ > 1}, and b = {x │ x+1/2-x ≤ 0.
7. What is the value of k? Is the solution set of the inequality 2x2+2kx+k/4x2+6x+3 < 1 about x R?
8. it is known that f (x) = log a (ax power-1) (a > 0, and a≠ 1).
(1) Find the domain of f(x);
(2) Discuss the increase or decrease of f(x);
(3) Solve the equation f (2x) = f- 1 (x)?
9. In arithmetic progression {a n}, a 10=230 = 230, A25 =-220, let the first negative term be a n and find n.
10. The difference between the seventh and fifth terms of the known geometric series {{a n}} is 48, the sum of the sixth and fifth terms is 48, and the sum of the first n terms is 1023. Find a 1, q, n?
1 1, the sequence {Cn} is known, where Cn = 2n power +3n power, and the sequence {Cn+ 1-Pcn} is a geometric series. Find the constant p?
12, it is known that the sum of the first n items in the sequence {{a n}} is Sn = 3N2+5N. In the sequence {BN}, b1= 8,64bn+1-bn = 0, and there is a constant c, so for any integer n, an+.
13, let {an} be a power of arithmetic progression and BN = (1/2), and it is known that B 1+B2+B3 = 2 1/8 and b1b2b3 =/kloc-.
14, known 4x power -9? 2 x+ 1 power +32 ≤ 0, find the function y = log 1/2 (x/2)? What are the maximum and minimum values of log 1/2(x/8)?
15 if x, y, z Y, z becomes arithmetic progression. (x+y)/2, (x+z)/4, (y+z)/8 are geometric series. Then the common ratio of these ratio columns is ().
16. The linear equations of vertex A(-4.2) of triangle ABC where the two median lines are located are 3x-2y+2=0 and 3x+5y- 12=0, respectively. Find the linear equation of BC edge.
17. it is known that L( 1):y=x, L(2):y=- root 3x/3, and there is a point p above two straight lines. If it intersects with P, let's make the vertical lines of L( 1) and L(2) respectively, and the vertical feet are A and B. It is known that |PA|=2 times the root number 2, and |PB|=2 times the root number 3. Find the coordinates of p.
18. It is known that two fixed points A(2.5), B(-2. 1), M and N are two fixed points on a straight line L passing through the origin, where m is in the first quadrant |MN|=2 times the root number 2. L parallel AB. If the intersection point C of AM and BN is on the Y axis, find the coordinates of point C. ..
19. Find the equation of circle passing through two points A(4.2) and B(- 1.3), and the sum of four intercepts on two coordinate axes is 2.
20. In the triangle ABC, it is known that |BC|=2. And | ab |/| AC | = m. Find the trajectory equation of point A and tell what the trajectory is.
2 1. It is known that circle C satisfies the following three conditions at the same time: 1. Tangent to the y axis. 2 the chord length of the line Y=X is twice as long as the root number 7; 3. The center of the circle is on the straight line X-3Y=0. An equation for finding a circle.
22. Let z be an arbitrary real number, and what is the graph of the set corresponding to point P( 1.2.Z)?