In order to express "no", we know the new book negative number, in order to express the opposite meaning of quantity, we also know the () number

In order to express "no", we know the new book negative number, in order to express the opposite meaning of quantity, we also know the () number

In order to express the opposite quantity, we also know the (opposite) number

What are the categories of natural numbers

① Divided into even and odd numbers
② Divided into prime, composite and 1

As shown in the figure, in the rectangle ABCD, ab = 8cm, BC = 10cm, fold one side of the rectangle ad so that point d falls on point F of BC side, the crease is AE, and calculate the length of CE

Let CE = x, EF = 8-x, CF = 12bc = 5, then in RT △ ECF, ef2 = CE2 + CF2, that is, (8-x) 2 = x2 + 52, the solution is x = 3916, so CE = 3916cm

X1 and X2 are two real root inequalities of the equation x ^ 2-mx-2 = 0. A ^ 2-5a-3 > = lx1-x2l is constant for any real number M
And the inequality ax ^ 2 + 2x-1 is greater than 0, there is no real number solution

∵ X1 and X2 are the two real roots of the equation
∴x1+x2=m x1x2=-2
|X1-x2 | = radical [(x1 + x2) ^ 2-4x1x2] = radical (m ^ 2 + 8)
When m belongs to [- 1,1], the root sign (m ^ 2 = 8) belongs to [2, 2,3]
So a ^ 2-5a-3 > = 3 holds
A > = 6 or A0 has no real solution
So the opening is down and delta

Given the coordinates of three points in space, find the normal vector of the plane
It means that if three points on the plane are explicitly specified, I can find the normal vector. Now when programming [given three points] - > [normal vector], I find that sometimes the equation with product of 0 is Trivariate once, sometimes bivariate once, and even one variate once, resulting in arbitrary values This is a very easy thing for human beings. The program is not easy to write. Now the problem is how to take the normal vector of any value or what to judge the equations when taking any value

In my opinion, the difficulty lies in solving equations. In general, equations are solved by formulas. You can check them~
There is another way, that is, in higher mathematics, the product of vectors is, in the final analysis, a formula

What should be paid attention to when using vertical division?

When calculating vertical division, pay attention to write the quotient from the highest position

As shown in the figure, in the cube ABCD-A, B, C, D, EF is the midpoint of edge AA, CC,: BC respectively! If AA, = 4, save VC BDF! (2) save the lines D, F and B on the opposite plane

This problem is very simple. I don't feel like I'm going to ask for help. I can draw a picture and mark it with letters

Calculation: (1 + 2 to the minus 1 / 8 power) × (1 + 2 to the minus 1 / 4 power) × (1 + 2 to the minus 1 / 2 power)

The original formula multiplies one (to the negative 1 / 8 power of 1-2) and divides another (to the negative 1 / 8 power of 1-2)
Then (negative 1 / 8 power of 1-2) (negative 1 / 8 power of 1 + 2) = (negative 1 / 4 power of 1-2)
(negative 1 / 4 power of 1-2)) × (negative 1 / 4 power of 1 + 2) = (negative 1 / 2 power of 1-2)
(negative 1 / 2 power of 1-2)) × (negative 1 / 2 power of 1 + 2) = negative 1 power of 1-2 = 1 / 2
The original formula = 0.5 / (negative 1 / 8 power of 1-2) = 1 / (7 / 8 power of 2-2)

It is known that the point P is the point on the vertical bisector of the line ab
It's urgent! It's urgent tonight!

∵ the distance from the point on the vertical bisector of the line segment to both ends of the line segment is equal
∴PA=PB

How to calculate 4 / 1X + 4 / 3x = 11 / 4

Multiply both sides by the common divisor 12
48X+16X=33
64X=33
X=33/64