What number should the question mark be, 8 4 9 2 10 5 4 2 3 4 2 5 Depressed! This should look better! Don't look at the ellipsis! 8…… 4… ；… 9…… 2… ；… 10…… five … 48…… ；…… 25…… ；……… ? 4…… 2… ；… 3…… 4… ；… 2…… five

What number should the question mark be, 8 4 9 2 10 5 4 2 3 4 2 5 Depressed! This should look better! Don't look at the ellipsis! 8…… 4… ；… 9…… 2… ；… 10…… five … 48…… ；…… 25…… ；……… ? 4…… 2… ；… 3…… 4… ；… 2…… five

1.(8-2) *(4+4) =48
2.(9-4)*(3+2) =25
3.(10-5)*(5+2) =35
The rule is: subtract two numbers from the left diagonal
Add two numbers on the right diagonal,
The multiplication of the two numbers is the number in the middle

2 26.4 6.6 13.6 1.7 10.8 2.7 what should be the number question mark?

2 26.4 6.6
6 13.6 1.7
2 10.8 2.7
Divide the second column by the first to get 4 8 4
First column + 2 = 4 8 4

The function f (x) = | lgx |, has 0

The snail climbs up along the shaft wall at the bottom of the well, 3M up in the daytime and 2m back in the evening. A well is 12m deep, climbing up from the bottom of the well, how many days can it climb to the wellhead?
Xiao Ming said: I think it will take 12 days
Xiao Hong said: I think it's only 11 days
Xiaomin said: I think it's 10 days
Who do you think is right? Why?

I climbed 3 meters every day. I didn't have to slide on the last day, so I climbed 3 meters on this day
It's been a long time before that
12-3 = 9 m
Climbing 3 meters every day, sliding 2 meters, actually climbing every day
3-2 = 1m
It's necessary to climb 9 meters
9 △ 1 = 9 days
All in all
9 + 1 = 10 days

If real numbers x, y and Z satisfy (x-z) 2-4 (X-Y) (Y-Z) = 0, then the following formula must be true ()
A. x+y+z=0B. x+y-2z=0C. y+z-2x=0D. z+x-2y=0

∵ (x-z) 2-4 (X-Y) (Y-Z) = 0, ∵ x2 + z2-2xz-4xy + 4XZ + 4y2-4yz = 0, ∵ x2 + Z2 + 2xz-4xy + 4y2-4yz = 0, ∵ (x + Z) 2-4y (x + Z) + 4y2 = 0, ∵ (x + z-2y) 2 = 0, ∵ Z + x-2y = 0

The base and area of a triangle are equal to those of a parallelogram. The height of parallelogram is 10cm, and the height of triangle is ()
A. 10cmB. 20cmC. 5crn

Let the height of triangle be H1, the height of parallelogram be H2, because H1 = 2S △ a, h2 = s △ a, so h2 = 12h1, so the height of triangle is twice that of parallelogram, and the height of triangle is: 10 × 2 = 20 (CM)

Given that m (4,2), f is the focus of the parabola y ^ 2 = 4x, find a point P on the parabola, which is PM + pf minimum, find P

Point m is inside the parabola
Let the distance from P to the guide line x = - 1 be D, then: pf = D
So, PM + pf = PM + D
The minimum value of PM + D is the distance from m to the guide line, which is 5
The point of intersection between the vertical line x = - 1 passing through M and the parabola is p
Yide: P (1,2)

Function extremum FX = 3x-x3

f(x)=3x-x^3
Derivation: F (x) '= 3-3x ^ 2 = 3 (1-x ^ 2)
Let f (x) '= 0, then 1-x ^ 2 = 0, so x = ± 1
Then:
f(x)max=f(1)=3-1=2
f(x)min=f(-1)=-3+1=-2

AB is the diameter of the circle O, point C is a point on the circle O, ad is perpendicular to point D, AC bisects ∠ DAB to prove that DC is the tangent of the circle o

It's not difficult to draw the following figure. Because AC bisects ∠ DAB, so ∠ DAC = ∠ BAC, and OA = OC, so ∠ Cao = ∠ OCA = ∠ DAC, you can get AD / / OC. Finally, ad is perpendicular to point D, so OC is perpendicular to CD. It is concluded that DC is the tangent of circle o

Given that the point P (3, m) is on a straight line passing through two points m (- 2,1) and n (- 3,4), then the value of M is

The line passing through M (- 2,1) and n (- 3,4) is y = - 3x-5
X = 3, y = m
m=-9-5=-14