The midpoint problem of conic chord To solve the linear equation of the chord of hyperbola with a (m, n) as the midpoint, we can use f (x1) - f (x2) to get the result. But why does it not exist?

The midpoint problem of conic chord To solve the linear equation of the chord of hyperbola with a (m, n) as the midpoint, we can use f (x1) - f (x2) to get the result. But why does it not exist?

The premise of point difference method is that there is intersection point between straight line and conic curve
Because X1 and X2 may not exist. When you set them, you have assumed that they exist

A math problem about Tangram!
Tangram is the crystallization of the wisdom of the working people in ancient China, which has been widely valued in the world

It is not surprising that this kind of game is produced in the long-term historical development because of its simple production and rich changes. For example, Archimedes' fourteen skilful boards in the 3rd century BC in the West are called the loculus Archimedes (Archimedes box) or stomachion (crazy toy) in the West

What does one digit after the exact decimal point mean

Keep one decimal place, that is, the hundredth, that is, the second decimal place, rounded

23605 use scientific notation to keep two significant numbers?

2.4×10^4

Difference ch ā () ch à () C ī ()

The difference is almost uneven

Given that the line y = KX + B is parallel to the line y = - 3x + 4 and passes through the point (3,0), the expression of this function is

The function expression is y = - 3x-9
Because: the straight line is parallel to the straight line y = - 3x + 4, then we can know that the slope of the straight line is the same as the known straight line, that is
k=-3
Because the straight line passing through the point (3,0) can be substituted to get b = - 9
So, the straight line is y = - 3x-9

There are 100 numbers written on the blackboard, i.e. 1,1 / 2,1 / 3,..., 1 / 100. In each operation, first select 2 numbers AB from the blackboard, then delete AB, and write the number a + B + AB on the blackboard. After 99 operations, the remaining number on the blackboard is ()
　　A.2012　　　B．101　　　C．100　　　D．99

1 + 1 / 2 + 1 * (1 / 2) = 2; 2 + 1 / 3 + 2 * (1 / 3) = 3; 3 + 1 / 4 + 3 * (1 / 4) = 4;... 99 + 1 / 100 + 99 * (1 / 100) = 100; this is to select, delete and add in order

Under the condition of heating, copper reacts with enough concentrated sulfuric acid to produce 0.56l sulfur dioxide (standard condition)? (2) What is the amount of reduced sulfuric acid?

When n (SO2) = 0.56l22.4l/mol = 0.025mol, Cu + 2h2so4 (concentrated) & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; CuSO4 + SO2 ↑ + 2H2O, then Cu + 2h2so4 (concentrated) & nbsp; & nbsp; & nbsp; & nbsp; & nbsp; CuSO4 + SO2 ↑ + 2H2O & nbsp; & nbsp; & nbsp; 1mol & nbsp

Given square ABCD, E on BD, EM ⊥ BC, en ⊥ CD, Mn = AE

Proof: make EP perpendicular to AB.EQ Perpendicular to ad
Then EP = EM EQ = en
APEQ = cnem is rectangular
Because the diagonals of two identical rectangles are equal
So, AE = Mn

After 0.35:4 reduction, it is (), and the ratio of 7 / 3:42% is ()

0.35:4=7:80
7/3:42%=7/3:21/50=50/9