The position of point (0,1,5) and point B (0, - 3,0) in the space rectangular coordinate system is special, and point a is in the space rectangular coordinate system___ On, point B is on_____ On? If we also know the three vertices a (2, - 1,4), B (3,2, - 6) and C (- 5,0,2) of a triangle, then the length of the middle line passing through point a is______ The coordinate of the center of gravity of this triangle is_______

The position of point (0,1,5) and point B (0, - 3,0) in the space rectangular coordinate system is special, and point a is in the space rectangular coordinate system___ On, point B is on_____ On? If we also know the three vertices a (2, - 1,4), B (3,2, - 6) and C (- 5,0,2) of a triangle, then the length of the middle line passing through point a is______ The coordinate of the center of gravity of this triangle is_______

1、 The position of point (0,1,5) and point B (0, - 3,0) in the space rectangular coordinate system is special. Point a is on the (YZ plane) and point B is on the (Y axis). The midpoint of B C is d (- 1,1, - 2), ad = under the root sign (3 & sup2; + 2 & sup2; + 6 & sup2;) = 7, the barycentric coordinate is the sum of three coordinates divided by 3, and the abscissa of barycentric is (2

If there is only one common point between the line y = KX + 1 and the left branch of hyperbola C: x2-y2 = 1, then the value of K is ()
A. （-1，1]B. k=2C. [-1，1]D. （-1，1]∪{2}

Given that there is only one common point between the straight line y = KX + 1 (1) and the left branch of hyperbola C: x2-y2 = 1 (2), the abscissa of the intersection point can be obtained to be less than 0

9 5 4 2 = 24 fill in operation symbol or bracket

(9-5)(4+2)

Let m = a + 1 / (A-2) (2)

M is greater than 4, n is less than 4, let A-2 = t 1 / A-2 = 1 / T greater than 1, M = 1 + 3 / T greater than 4, the following is almost the same, we need to use the minus function of logarithmic function

Solving some math problems in grade two
1. It is known that the height of the waist of an isosceles triangle is equal to half of the length of the waist, then a base angle of the isosceles triangle is equal to__________ .
2. If one right side of a right triangle is 5 and the median line on the hypotenuse is 6.5, then the other right side is 5_________ .
3. In triangle ABC, if angle c = 90 ° and C = 2A, then angle B=______ Degree
4. If the lengths of the three sides of a triangle are 6, 8 and 10, what is the radius of the circumcircle of the triangle________ The radius of the inscribed circle is_________ .
5. We use X and y to express the degree of the top and bottom angles of isosceles triangle, respectively. The analytic expression and domain of the function between Y and X are_________ .
6. If the intersection of line y = 2x-1 and line y = M-X is in the third quadrant, then the value range of M is________ .
7. The area of the triangle formed by the image of the function y = - x + 2 and the coordinate axis is________ .
8. If the intersection coordinates (m, 8) of the line y = - x + A and the line y = x + B, a + B=________ .
If the area of the triangle formed by the line y = - 2x + K and the coordinate axis is 9, then the value of K is_________ .
9. Given the function y = K / X (k is a constant which is not equal to zero), y decreases with the increase of X in each quadrant. If point a (3, K & sup2; - 1) is on the image of this function, then the value of K is________ .
10. It is known that Y-3 is in positive proportion to x, and when x = 2, y = 7: 1
(1) Find the functional relationship between Y and X;
(2) When x = - 1 / 2, find the value of Y;
(3) Translate the function image to pass the point (2, - 1). Find the analytic expression of the line after translation
11. As shown in the figure, point P is the focus of an image with an inverse scale function and a positive scale function y = - 2x, PQ is perpendicular to the X axis, and the coordinates of the perpendicular foot Q are (2,0)
(1) Find the analytic expression of the inverse proportion function (the final answer is y = - 8 / x)
(2) If point m is on the image of the inverse scale function and the area of triangle MPQ is 6, the coordinates of point m are obtained

1. It is known that the height of the waist of an isosceles triangle is equal to half of the length of the waist, then a base angle of the isosceles triangle is equal to 75 ° or 15 °
2. If one right side of a right triangle is 5 and the center line on the hypotenuse is 6.5 long, then the other right side is 12.5 long
3. In triangle ABC, if angle c = 90 ° and C = 2A, then angle B = 60 degrees
4. If the lengths of the three sides of a triangle are 6, 8 and 10, then the radius of the circumcircle of the triangle is 5_ The radius of the inscribed circle is 2
5. The degree of vertex angle and base angle of isosceles triangle are expressed by X and Y respectively. The analytic expression and domain of definition between Y and X are y = 90-x /; 0

Is there any special way to remember the common mathematical set symbols n, N +, Z, Q, R
I'm always confused

If you understand, you can remember,
I don't think it's necessary to remember it in any special way
Just understand what it means

English verb ing
Are you going to study

The present participle of a verb consists of:
1) Direct addition - ing
study-- studying
2) Ending with E, go to e and add - ing
like-- liking
3) Stress words with only one consonant at the end of a closed syllable, double write the consonant and add - ing
stop-- stopping
4) For a few words that end with IE and stress the open syllable, change ie into y and add - ing
Die -- dying lie -- lying lie -- lying
I didn't go to y

There are three different points a (x1, Y1), B (4,9 / 5), C (X2, Y2) on the ellipse x ^ 2 / 25 + y ^ 2 / 9 = 1. The distance between a (x1, Y1), B (4,9 / 5), C (X2, Y2) and the right focus f (4,0) forms an arithmetic sequence. It is proved that the vertical bisector of line segment AC passes through a fixed point

I think it should be like this: AF, BF, CF form an arithmetic sequence → their abscissa x1, 4, X2 form an arithmetic sequence (this is derived from the formula of focal radius P = a-ex, and x1, X2 are between the interval [3,5]) let X1 = 4-T; x2 = 4 + t, the sequence form: 4-T, 4, 4 + T, then X1 + x2 = 8; the midpoint is horizontal

Please give some four operations

67+15-4*5/57

If two of the equations lg2x + (LG2 + Lg3) lgx + lg2lg3 = 0 are X1 and X2, then what is the red

lg2x+(lg2+lg3)lgx+lg2lg3=0
(lgx)^2+(lg2+lg3)*lgx+lg2lg3=0
(lgx+lg2)(lgx+lg3)=0
Lgx + LG2 = 0, or lgx + Lg3 = 0
X = 1 / 2, or x = 1 / 3