Let a = true, B = false, C = true, d = false, the following logic operation expression value is true, there is () A. (A∧B)∨(C∧D∨ A) B. (( A∧B)∨C)∧ D C. (B∨C∨D)∨D∧A D. A∧(D∨ C)∧B What do the symbols mean? What do you mean by these two?

The operators of∧and∨ logical calculus have two operational variables
Λ is logical conjunction, or logical and, if and only if its two operation variables are true, the result is true
Truth table:
p q ∧
It's true, it's true
True or false
False, true and false
Fake fake fake
∨ is a logical disjunction, or logical or, if and only if its two operational arguments are false, the result is false
Truth table:
p q ∨
It's true, it's true
True false true
False and true
Fake fake fake
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Note: in the following calculation process, use &, | to represent and or, use = to represent equivalence, and use 0 and 1 to replace false and true
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A.true
(A&B)|(C&D|A)=(0)|(0|1)=0|1=1
B.false
((A&B)|C)&D=(0|C)&D=1&0=0
C.true
(B|C|D)|D&A=(0|1|0)|0&1=1|0&1=1|0=1
(B|C|D)|D&A=(0|1|0)|0&1=1|0&1=1&1=1
D.false
A&(D|C)&B=1&1&0=0
The answer is AC. (note that in some books ∧ has priority over ∨, while in other books ∨, the two are at the same level, so the C option is ambiguous, but the answer happens to be the same.)
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[original response group]

2. Let a = true, B = false, C = true, d = false, the following logic operation expression value is true ()
A．(A∧B)∨(C∧D∨「A) B．((「A∧B) ∨C)∧「D
C．(B∨C∨D) ∧D∧A D．A∧（D∨「C）∧B
Don't plagiarize in 08noip

B. You should be kind. The answer should be tied. If you add more points, it will be perfect_ ∩)o
((「A∧B) ∨C)∧「D
C = true, d = true, so the above expression is true

The meaning, volume and surface area of all solid figures

Circumference of rectangle = (length + width) × 2
Perimeter of square = side length × 4
Area of rectangle = length × width
Area of a square = side length × side length
Area of triangle = bottom × height △ 2
Area of parallelogram = base × height
Area of trapezoid = (upper bottom + lower bottom) × height △ 2
Diameter = radius × 2 radius = diameter △ 2
Circumference of circle = circumference × diameter=
Circumference × radius × 2
Area of circle = circumference × radius × radius
The surface area of a cuboid=
(L × W + L × H + W × h) × 2
Cuboid volume = length × width × height
The surface area of cube is edge length × edge length × 6
The volume of cube = edge length × edge length × edge length
Side area of cylinder = circumference of bottom circle × height
Surface area of cylinder = area of upper and lower bottom surface + side area
Volume of cylinder = bottom area × height
The volume of the cone = the area of the bottom × the height △ 3
Cuboid (cube, cylinder)
Volume = bottom area × height

Given that the function FX is equal to the square of 2x - 3x plus 1, find the value of F (- radical 2), f (a plus 1)

f(x)=2x2-3x+1
therefore
f(-√2)=2*2+3√2+1
=5+3√2
f(a+1)=2(a+1)^2-3(a+1)+1
=2(a2+2a+1)-(3a+3)+1
=2a2+4a+2-3a-3+1
=2a2+a
Children's shoes

The product of two continuous even numbers must be divisible by what? A is divisible by a multiple of 4, B is divisible by 8, C is divisible by a multiple of 8

B because the problem contains certain two words, let's set it as 2n and 2n plus 2, s = 2n * (2n + 2) = 4N (n + 1), where n is an integer from negative infinity to positive infinity, no matter n is odd or even, n (n + 1) is even, so n (n + 1) can be expressed as 2K, s = 8K, so it must be divided by eight, while other options only emphasize multiple, not many times. If 8 times of 4 and 4 times of 8 do not meet the conditions

If the distance between a point on an ellipse and two focal points is 2a, is the distance between this point and one of the focal points a
For example, can 2A = 10 introduce a = 5? If not, when can it be launched
Is the distance from any point of the ellipse to one of the focal points F1 a? What does it have to do with the focal radius?

The sum of distances from a point to two focal points is 2a, where 2a is the sum of two distances
2A = 10 can directly deduce a = 5;
The distance from the end point of the minor axis of the ellipse to the two focal points is equal, both are a;
The connecting line between any point m on conic curve and conic focus is called conic focus radius, which is not a fixed value
As for ellipses, the radius passing through the right focus R = a-ex; the radius passing through the left focus R = a + ex; the radius passing through the upper focus R = a-ey; the radius passing through the lower focus R = a + ey

X = 2 * 3 * 5 * 7 * 11 * 13 * 17 * 19 * 23 * 29 *. N (n is prime number), prove that x + 1 is prime number

This conclusion is not correct
2*3*5*7*11*13+1=30031=59*509.

Please change the following functions into the situation of y = a (X-H) square + K through the formula, and then directly write out the opening direction of the function image, the maximum value of the vertex symmetry axis function y
1）y=x²+x （2）y=-2(x+2)(x-4)

(1)y=(x+1/2)^2-1/4
Opening up
The vertex coordinates are (- 1 / 2, - 1 / 4)
Axis of symmetry x = - 1 / 2
Minimum - 1 / 4
（2）y=-2(x-1)^2+18
Opening down
Vertex coordinates are (1,18)
Axis of symmetry x = 1
Maximum 18

If point a (m, n) is on the image with inverse scale function y = - 3 / x, then the value of Mn is?

If point a (m, n) is on the image with inverse scale function y = - 3 / x,
Then n = - 3 / M
mn=-3
The value of Mn is - 3

Let x, y and Z respectively represent a digit in the ternary system. If the equation XY + ZX = xYx holds in the ternary system, then the equation XY * ZX holds in the ternary system=
() also holds
A.YXZ B.ZXY C.XYZ D.XZY

The answer is B

Let a = true, B = false, C = true, d = false, the following logic operation expression value is true, there is () A. (A∧B)∨(C∧D∨ A) B. (( A∧B)∨C)∧ D C. (B∨C∨D)∨D∧A D. A∧(D∨ C)∧B What do the symbols mean? What do you mean by these two?