1. In the spatial rectangular coordinate system, if A-2,3) and B (3,2-5) are known, what is the midpoint coordinate of the line segment AB?
A.(- 1，-2.4)B.(-2.0. 1)C.(2.0，-2)D.(2.0。 - 1)
2. if the vector A = (1, 0), b=(2,-1, 2), and the cosine of the angle between a and b is 1, then the real number is equal to D.0 or a.0b.-3. The known side length is the square of 1. Then the value of A0. AC is () a.-1 b.0c. 1 d.24. A 1 0.0 is known), B(0,10), C(0.0,1).
At ().
A.(- 1， 1，I)B .(，- 1 1)
5. In the triangular pyramid P-ABC, ABC is an equilateral triangle, PAC is an isosceles right triangle PA=PC=4, the plane PACL is ABC, and D is the midpoint of AB. What is the cosine of the angle formed by a straight line AC and PD on different planes?
6. Point P is out of the plane of rectangular ABCD, and plane ABCDC of PA 1 is the midpoint of line segment AP, AB = 3, BC = 4 and PA = 2, so the distance from point P to plane BQD is () R 13825.
7. (Multiple choices) Given the directional quantities a= (,-l, m) and b=(-2, m- 1, 2), the following conclusion is correct ().
A. if laE2, then m=2. B. If aLb, m=- 1. There is no real number in c, so that a = b.d. If a.b=- 1, then a+b=(- 1, -2, -2).
8. (Multi-choice) Given the side length of the cube ABCD-ABCD is 1, points E and 0 are the midpoint of AB and AC respectively, and P is inside the cube and satisfies AP=ABAD. The following statement is correct.
The distance from point A to the straight line BE is 5. The distance from point 0 of b to plane ABCD is 2. The distance between plane ABD and plane BCD of C is 3.
The distance from point P of D to straight line AB is 25.
9. Known AB=( 15. -2) and BC=(3, 1,). If ABLBC, BP = (-3) and BPL plane ABC, then x+y=_
10. As shown in the figure, in the regular pyramid P-ABCD, PA=AB, point M is the midpoint of PA, BD=ABN If MNLAD, and real number A=.