If vector a and B satisfy | vector a | = | vector B | = 1, and vector A &; vector B + vector B &; vector b = 3 / 2, Then the angle between vector a and vector B is ()

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• 1. It is known that the image of quadratic function y = x2 + BX + C passes through two points a (0,1), B (2, - 1). (1) find the value of B and C; (2) try to judge whether the point P (- 1,2) is on the parabola
• 2. The analytic region of the following function f (x) is pointed out and its derivative is obtained （1）Z^3+2iZ ;
• 3. Given that real numbers x, y, Z satisfy X-Y = 8, XY + Z2 = - 16, then x + y + Z=______ ．
• 4. A-B + C = 2 (1) a + B + C = 1 (2) 4A + 2B + C = 3 (3) how to solve the ternary linear equations?
• 5. The right focus of hyperbola C x ^ 2 / A ^ 2-y ^ 2 / b ^ 2 = 1 (a greater than 0, b greater than 0) is f passing F, and the intersection C of straight line with slope root 3 is at two points a and B If the vector AF = 4, find the eccentricity of C with the vector FB
• 6. It is known that the quadratic equation AX2 + BX + C = 0 with respect to X. when the coefficients a, B and C satisfy a-2b + 4C = 0, there is a root which can be determined. The root is: - (excluding a, B and C)
• 7. When | x | is less than or equal to 1, find the minimum value of square x-2ax + a of quadratic function y = X When | x | is less than or equal to 1, find the minimum value of square x-2ax + a of quadratic function y = X
• 8. How to calculate the area of irregular figure?
• 9. P is a point on the ellipse x ^ 2 / 25 + y ^ 2 / 16 = 1, F1 and F2 are the focus. If ∠ f1pf2 = 30 °, then the area of △ f1pf2 is Why let Pf1 = m, PF2 = 10-m, and then use Pythagorean theorem to calculate that there is no solution Wrong number for ∠ f1pf2 = 90 °
• 10. Given the line L: y = 3x + 3, find: (1) the equation of the line x-y-2 with respect to the line L symmetric, (2) the equation of the line L with respect to the line m (3,2) symmetric
• 11. Space is very difficult, but some people say that the space vector method can solve all geometric problems, so ask the space vector method to prove that a straight line is parallel to a plane? Yes, please say. Attach a topic, please use the space vector method to prove Q: as shown in the figure, in the cube abcd-a1b1c1d1, E is the midpoint of dd1, verification: BD1 / / plane AEC
• 12. Let a = {x | X & # 178; + (M + 2x) + 1 = 0, X ∈ r}, B = {x | x ＞ 0}, if a ∩ B = & # 8709;. Find the value range of real number M Let a = {x | X & # 178; + (M + 2) x + 1 = 0, X ∈ r}, B = {x | x ＞ 0}, if a ∩ B = & # 8709;. Finding the value range of real number m
• 13. How to deduce LNA equal to B times of E from B power of a?
• 14. |What is the relationship between the scalar product | of vector a and vector B and | a | B | Why?
• 15. Who is going to talk about the definition, properties and formulas of the inner center, outer center, center of gravity and perpendicularity of a triangle? be deeply grateful Come on
• 16. The parameter equation is x = cost, y = Sint, 0 ″ t ″ 2pi x=cost,y=sint,0《t《2pi The book says it's a circle, but I think it's a circle Why does t have to move on a circle if t is a straight line?
• 17. What figure does axisymmetric figure refer to? What two parts of figure does axisymmetric figure refer to
• 18. On the 1:30000 scale map, it is measured that a highway is 5 cm long, and it takes 6 days to complete the joint construction by team a and team B. the work efficiency ratio of team a and team B is 2:3. How many meters does team a repair every day?
• 19. Why don't stars fall from the sky?
• 20. As shown in the figure, it is known that ∠ AOB = 90 °, EOF = 60 °, OE bisects ∠ AOB, of bisects ∠ BOC, and the degrees of ∠ AOC and ∠ cob are calculated