The concept of mathematical coefficient times

The concept of mathematical coefficient times

The number of monomials = the exponential sum of all the letters in the monomials, and individual letters and numbers are also monomials
The degree of a polynomial = the degree of the monomial with the highest degree in the polynomial
Coefficient: the number part before the letter, the letter coefficient of 1 can be omitted
The concepts in the book are all examples

Examples of definition and judgment in mathematical equation of one variable
For example: (3-A) x | 2a-5 | (| 2a-5 |) is an index) + 7 is a linear equation of one variable, such a question type!

If (3-A) x ^| 2a-5 | + 7 = 0 is a linear equation with one variable,
Then 3-A ≠ 0 and | 2a-5 | = 1,
That is, a ≠ 3 and 2a-5 = ± 1,
∴a=2.
The equation is x + 7 = 0, and x = - 7 is the solution of the equation

Seek the mathematics concept arrangement of the first day of junior high school!

Real number: rational number and irrational number are called real number. Rational number: integer and fraction are called rational number. Irrational number: irrational number refers to infinite non cyclic decimal. Natural number: the number of objects

It is known that the three special solutions of the second order non-homogeneous linear differential equation are Y 1 = 1, y 2 = x, y 3 = x ^ 2. The general solution of the equation is given
If Y1 and Y2 are two special solutions of the equation P1 (x) y '' + P2 (x) y '+ P3 (x) y = f (x), then y1-y2 are the solutions of the equation P1 (x) y' '+ P2 (x) y' + P3 (x) y = 0

If Y1 and Y2 are the two special solutions of the equation P1 (x) y '' + P2 (x) y '+ P3 (x) y = f (x), then y1-y2 are the special solutions of the equation P1 (x) y' '+ P2 (x) y' + P3 (x) y = 0. Using the above conclusion, we can see that y = X-1 and y = x & sup2; - 1 are the special solutions of the homogeneous equation corresponding to the second order non-homogeneous differential equation, because these two special solutions are not

20% more than 90 square meters is () square meters, and 90 cubic meters is 20% less than () cubic meters?

20% more than 90 square meters is (108) square meters, and 90 cubic meters is 20% less than (75) cubic meters

8888×9911×7777×6666
How to do simple algorithm

1111×（8+7+6+9）-1111×（99-11）＝4566662648970576

Given a positive proportional function and a first-order function, their images pass through the point P (- 3,3), and the image of the first-order function intersects with the Y axis at the point Q (0, - 2), the analytic expressions of the two functions are obtained

Let the analytic expression of the positive proportional function be y = K1X, ∵ it passes through the point P (- 3,3), ∵ 3k1 = 3, and the solution is K1 = - 1, ∵ the analytic expression of the positive proportional function is y = - x; let the analytic expression of the primary function be y = K2 + B, ∵ it passes through the point P (- 3,3), and the point Q (0, - 2), ∵ 3k2 + B = 3B = - 2, and the solution is K2 = - 53B = - 2, so the analytic expression of the primary function is y = - 53x-2

The volume of a cuboid is 5.4 cubic meters, the height is 9 decimeters, and the bottom area is () square meters

A cuboid has a volume of 5.4 cubic meters, a height of 9 decimeters and a bottom area of (6) square meters
Volume divided by height is the bottom area, pay attention to the unit

3.4.5.7 calculate 24 points
The more, the better

3*(7-4+5)=24
4*3*(7-5)=24
4*5+7-3=24
3*4+5+7=24
Enough

What is (COS θ - sin θ) / (COS θ + sin θ) equal to

(cosθ-sinθ)/(cosθ+sinθ)
=(1-tanθ)/(1+tanθ)