How to judge the maximum value, opening direction, vertex coordinates, increase or decrease of quadratic function?

How to judge the maximum value, opening direction, vertex coordinates, increase or decrease of quadratic function?

In the quadratic function, the judgment of the maximum value needs to transform the function y = ax ^ 2 + BX + C into y = a (x + m) ^ 2 + n,
1、 When a is a positive number (i.e. A. & gt; 0), then the opening of the function is upward, and there is a minimum value, decreasing on the left side of the symmetry axis line x = - m, and increasing on the right side of the symmetry axis, and the function has a minimum value, Ymin = n. at this time, the vertex coordinate is (- m, n)
2、 When a is a negative number (i.e. a & lt; 0), then the opening of the function is downward and has the maximum value, which increases on the left side of the symmetry axis line x = - M and decreases on the right side of the symmetry axis, and the function has the maximum value, y max = n. at this time, the vertex coordinate is (- m, n)
If the focus of the ellipse is in the y-axis, a = 4, C = root 15, find its standard equation
b^2=a^2-c^2=1
So the elliptic equation is
y^2/16+x^2=1
Positive solution
How to calculate permutation and combination
（1）x:y:z=3:2:5,2x+3y+8=5 （2）5x-3y+z=5,4x+3y-2z=9x-5y-z=-17
(1) Let x = 3T, then y = 2T, z = 5T be substituted into 2x + 3Y + 8 = 5 to get 6T + 6T + 8 = 5, t = - 1 / 4, x = - 3 / 4Y = - 1 / 2Z = - 5 / 4 (2) (1) × 2 + (2) to get 14x-3y = 19 (4) (1) + (3) to get 6x-8y = - 12 (5) to solve the equations (4) (5) to get x = 2Y = 3, and substitute x = 2, y = 3 into (1) to get 10-9 + Z
When m = -, the solution of equation 5x-2 = 4x + 1 is the same as that of equation 2 (x-1) + 2m = - (M + 1)
Solve the equation 5x-2 = 4x + 1
X=3
Substituting x = 3 into the formal
2(x-1)+2m=-(m+1)
4+2m=-m-1
5+3m=0
m=-5/3
First simplify, then evaluate: 1 / 2x-2 (x-1 / 3Y ^ 2) + 3 (- 1 / 2x + 1 / 9y ^ 2), where x.y satisfies (X-2) ^ 2 + y + 3 = 0
∵ (X-2) ^ 2 + y + 3 = 0 ∵ x = 2, y = - 3 ∵ 1 / 2x-2 (x-1 / 3Y ^ 2) + 3 (- 1 / 2x + 1 / 9y ^ 2) = 1 / 2x - 2x + 2 / 3Y & # 178; = (1 / 2-2-3 / 2) x + (2 / 3 + 1 / 3) y & # 178; = - 3x + Y & # 178; = - 3 × 2 + (- 3) & # 178; = - 6 + 9 = 3
Write out the ellipse and standard equation suitable for the following conditions: (1) a = 4, B = 1, focus on X-axis; (2) a = 4, C = root 15, focus on y-axis
（1）
x²/16+y²=1
（2）
b²=a²-c²=16-15=1
therefore
x²+y²/16=1
The only number of machines in the form of true value 0 is
1. For the representation of true value 0, the only machine number is
A. Original code B. BCD code C. complement code D. inverse code
2.（76.54）8=
A.(3E.B)16 B.(111110.10010)2 C.(62.6835)10 D.(110111.1011)2
3. The correct description of Alu in computer is
A. Only do arithmetic operation, not logic operation B. only do addition
C. All the above answers are wrong
4. In register indirect addressing mode, the operands are stored in the
A. General purpose register B. stack C. main memory unit D. instruction
5. The largest of the following unsigned numbers is
A. (01101) two B. (12) eight C. (0c1) sixteen D. (20) ten
6. In order operation of floating point addition and subtraction
A. Adjust the order code of clamour to be the same as that of Jiaotong University
B. Adjust the order code of clamour to be the same as that of Jiaotong University
C. Adjust the order code of the added (subtracted) number to be the same as that of the added (subtracted) number
D. Adjust the order code of the adder (subtracted) to be the same as that of the adder (subtracted)
7. What's right
A. Interrupt mode is generally used to handle random service requests
B. Once the external device sends interrupt request, it can get the response of CPU immediately
C. Once an external device sends an interrupt request, the CPU should respond immediately
D. Interrupt mode can be used for CPU requests to peripheral devices
8 storage cycle is
A. The main contents of this paper are as follows: the read-out time of memory; B. the write-in time of memory; C. The minimum interval between two consecutive memory operations; D. the average read-out and write-in time of memory;
Semiconductor dynamic memory needs to be refreshed
A. The storage content has been modified. B keeps the MOS tube in the state
B. According to the requirements of CPU, the contents of memory cell D are updated in time
10. The following description of interruption function is incorrect
A. Running CPU and Togolese IO devices working in parallel
B. Data transmission of Datong is realized without CPU intervention
C. Run the user intervention machine
D. Realize the connection between processors in multiprocessor system
1.A 2.C 3.D 4.C 5.C
6. AB 7. Don't know 8. C 9. D 10. A
1. Bracket 8x + 9x = 73,17x-3y = 74 2. Bracket 4x-3y = 3,3x-2y = 53 · bracket 5x-3y = 2,2x-3x = - 10
Solving equations of first order with two variables: process
1. Bracket 8x + 9x = 73 ①, 17x-3y = 74 ②
② X 3: 51x-9y = 222 ③
① + 3: 59x = 295, x = 5
So, x = 5, y = 11 / 3
2. Brackets 4x-3y = 3 ①, 3x-2y = 5 ②
① The result is: 8x-6y = 6.3
② 9x-6y = 15
④ - 3: x = 9, substituting x = 9 into 1, 36-3y = 3, y = 11. So x = 9, y = 11
3. Brackets 5x-3y = 2 ①, 2x-3x = - 10 ②
From ②, we can get: - x = - 10, x = 10
Substituting x = 10 into (1), 50-3y = 2, y = 16. So x = 10, y = 16
1. Bracket 8x + 9x = 73 ①, 17x-3y = 74 ②
② X 3: 51x-9y = 222 ③
① + 3: 59x = 295, x = 5
So, x = 5, y = 11 / 3
2. Brackets 4x-3y = 3 ①, 3x-2y = 5 ②
① The result is: 8x-6y = 6.3
② 9x-6y = 15
④ (3) get: x = 9, substitute x = 9 into (1,...)
1. Bracket 8x + 9x = 73 ①, 17x-3y = 74 ②
② X 3: 51x-9y = 222 ③
① + 3: 59x = 295, x = 5
So, x = 5, y = 11 / 3
2. Brackets 4x-3y = 3 ①, 3x-2y = 5 ②
① The result is: 8x-6y = 6.3
② 9x-6y = 15
④ - 3: x = 9, substituting x = 9 into 1, 36-3y = 3, y = 11. So x = 9, y = 11
3. Brackets 5x-3y = 2 ①, 2x-3x = - 10 ②
From ②, we can get: - x = - 10, x = 10
Substitute x = 10 into 1, 50-3y = 2, y = 16. So x = 10, y = 16! ~ ~ ~ ~ ~ ~ ~ please give me a favor. Put it away
If the solution of the equation x = 9 + 4x is the same as that of the equation 5x-2m, then M =?
The solution of ∵ x = 9 + 4x is the same as that of equation 5x-2m = 0
3x=﹣9
x=﹣3
5x-2m=0
x=2m/5=﹣3
∴m=﹣7.5