The general solution of the equation with absolute value in high school mathematics The solution of linear equation and quadratic equation with letter coefficient, the distribution of roots of quadratic equation with letter coefficient The solution of one variable linear equation and one variable quadratic equation with absolute value The solution of linear inequality of one variable with letter coefficient and quadratic inequality of one variable The linear inequality of one variable with absolute value

For example, the square of quadratic function y = x + 2x + 3 can be written as f (x) = x2 &; 2x + 3, and f (x0) is the function value when x = x0. For example, f (0) = 02 &; 2 &; 0 + 3 = 3
2. The image of quadratic function f (x) = AX2 + BX + C (a > 0) is a parabola with x = - B / 2A as symmetry axis and (- B / 2a, (the square of 4ac-b) / 4A) as vertex
3. Properties: when a > 0, the opening is upward, when x = - B / 2a, f (x) has the minimum value;
A0) are x1, X2, and x1

240 hectares is equivalent to several parts of a square kilometer

240 ha = 12 / 5 km2

Let f (x) = 1 (1 ≤ x ≤ 2), X-1 (2)

g(x)=1-ax (1≤x≤2)；x-1-ax(2

1 = [12 / (x + 12 + 24)] ^ 2 times X. how can this equation be solved?

That is, (x + 36) ² = 144x
x²+72x+1296=144x
x²-72x+1296=0
(x-36)²=0
x=36

Root 3 (tan50 ° tan70 °) - tan50 ° - tan70 °

Let me help you! We found that: 50 ° and 70 ° can synthesize 120 °; tan120 = (tan70 + tan50) / (1-tan70tan50), so tan70 + tan50 = tan120 (1-tan70tan50) = - √ 3 (1-tan70tan50) original formula: = √ 3tan70tan50 ° - (tan70 + tan50) = √ 3tan70tan50 + √ 3 (1-tan70t

If 2Y & # 178; + Y-2 is 3, 4Y & # 178; + 2Y + 1, 3ax & # 178; - BX-1 = 0 and ax & # 178; + 2bx-5 = 0 have the same root-1, and the values of a and B are obtained

2y²+y-2=3
∴2y²+y=5
4y²+2y+1
=2(2y²+y)+1
=2×5+1
=11
X = - 1 is substituted into 3ax & # 178; - BX-1 = 0 and ax & # 178; + 2bx-5 = 0
We obtain 3A + B-1 = 0
a-2b-5=0
The solution is a = 1
b=-2

Grandma raised a group of chickens and ducks, a total of 180, the number of chickens is four times that of ducks, how many chickens and ducks each?

A: there are 144 chickens and 36 ducks

What is Tan 2 / 3?

Tan (2 / 3) radian ≈ 0.78684288947297732996687854551701
（tan2）/3≈-0.72834662108717299721443536743789

The square of - 2x - 5x - 3 = 0 is solved by formula method

Use
solution
：2X^2-5X-3=0.
Divide both sides of the equation by 2 to get (x ^ 2-5x / 2-3 / 2 = 0)
The result is (x ^ 2-5x / 2 = 3 / 2)
The formula is (X-5 / 4) ^ 2-25 / 16 = 3 / 2
∴（（x-5/4)^2= (7/4)^2 ）.
∴X1=（3 ）,X2=（ -1/2）

The image with F (x) = sin (2x - π / 3) is shifted to the right by φ (φ > 0) unit length. The obtained image is symmetric about the y-axis, and the minimum value of φ is obtained

The analytical formula of the right shift of φ is as follows:
y=sin[2(x-φ)-π/3]
y(0)=sin(-2φ-π/3)=±1
-2φ-π/3=±π/2
The smallest positive number φ = π / 12