Judge the parity of sign function SGN (x) = {1, X ∈ (0, + ∞); 0, x = 0; - 1, X ∈ (- ∞, 0) Wuwu. I can't do a lot of questions. Please help me!

Judge the parity of sign function SGN (x) = {1, X ∈ (0, + ∞); 0, x = 0; - 1, X ∈ (- ∞, 0) Wuwu. I can't do a lot of questions. Please help me!

When x > 0, SGN (x) = 1
-x

A = 0.6 ^ 2, B = log20.6, C = 2 ^ 0.6, compare the size
Log2 0.6 means the logarithm of 0.6 with 2 as the base,

0

A = 0.3 square, B = log2 ^ 0.3, C = 2 ^ 0.3 how to compare the size

b=log2^0.31
0b

Given that a = log20.3, B = 20.3, C = 0.30.2, the size relation of a, B, C is ()
A. a＞b＞cB. b＞a＞cC. b＞c＞aD. c＞b＞a

∵ a = log20.3 ＜ log21 = 0, B = 20.3 ＞ 20 = 1, 0 ＜ C = 0.30.2 ＜ 0.30 = 1, ∵ B ＞ C ＞ a

How many cubic meters is a ton of concrete equal to?

Considering that 1 cubic meter of concrete is about 2.5 tons
Then 1 ton of concrete is about 0.4 cubic meters

Factorization with square difference
Only the first person who gives the process. Thank you
(m+n)^2-n^2
49(a-b)^2-16(a+b)^2
(2x+y)^2-(x+2y)^2
(x^2+y^2)^2-x^2y^2
3ax^2-3ay^4
Give the process... Thank you

(m+n)^2-n^2=(m+n+n)(m+n-n)=m(m+2n)
49(a-b)^2-16(a+b)^2 =(7a-7b+4a+4b)(7a-7b-4a-4b)=(11a-3b)(3a-11b)
(2x+y)^2-(x+2y)^2 =(2x+y+x+2y)(2x+y-x-2y)=3(x+y)(x-y)
(x^2+y^2)^2-x^2y^2 =(x^2+y^2+xy)(x^2+y^2-xy)
3ax^2-3ay^4 =3a(x+y^2)(x-y^2)

After the vertex of the second function y = - 2x & # is moved to (- 3,2), the analytic expression of the function is?

After the vertex of the second function y = - 2x & # 178; is moved to (- 3,2), the analytic expression of the function obtained is that the vertex coordinates of? Y = - 2x & # 178; are (0,0)
Moving to (- 3,2) can be understood as: first move 3 units to the left and then move 2 units up
Y = - 2x & # 178; y = - 2 (x + 3) &# 178; y = - 2 (x + 3) &# 178; y = - 2x & # 178; y = - 2 (x + 3) &# 178; y = - 2 (x + 3) &# 178; y = - 2 (x + 3) &;
If you move 2 units up, you will get: y = - 2 (x + 3) &# 178; + 2 is the expected adoption

When a cube with static volume v. and static mass M. moves along one edge at a speed V close to the speed of light in vacuum, its volume mass and density are calculated

If there is no one to answer, I will answer you tomorrow. Really! Now I'll answer: first of all, it's a relativistic problem. That is, when the speed of an object is close to the speed of light, the mass of the object will increase, the linearity will shrink, and the motion time will expand. Relativistic mass: M '= m / (1-V ^ 2 / C ^ 2) ^ (1 / 2) time expansion: t' = t / (1-V ^ 2 / C) ^ (1 / 2) ^ (1 / 2) time expansion: t '= t / (1-V ^ 2 / C

9 * 11 * 101 * 10001 results
Example: (200-5) * (200 + 5)
＝200²-5²
＝39975

99999999

In the plane rectangular coordinate system x0y, the analytic expression of parabola is y = 1 / 4x & # 178; + 1, the coordinate of point C is [- 4,0], the vertices a and B of parallelogram oabc are on the parabola, AB and Y axis intersect at point m, known point Q [x, y] is on the parabola, point P [T, When the quadrilateral cmqp is a trapezoid with MQ and PC as the waist: find the analytic function of T with respect to X and the value range of the independent variable x
[please make the analysis of each answer very clear, there will be wealth after adoption]

(1) the parabola is above the x-axis, oabc is a parallelogram, ab = OC = 4,
∵ the parabola is symmetric about the y-axis, and the abscissa of ∵ A is 2,
∥ a (2,2), ab ∥ X axis, ∥ m (0,2)
(2) the analytical formula of CM is y = 1 / 2x + 2,
According to the meaning: PQ ‖ cm,
The line passing through P (T, 0) and parallel to cm is set as y = 1 / 2x + B,
0=1/2t+B,B=-1/2t,∴Y=1/2X-1/2t,
Q (x, 1 / 4x ^ 2 + 1) is on a straight line,
∴1/4X^2+1=1/2X-1/2t,
t=-1/2X^2+X-2
When Q coincides with a and B, the quadrilateral is parallelogram. When p coincides with C, the quadrilateral does not exist,
Ψ x ≠ - 2 and X ≠ 2 and X ≠ - 4