Who can teach me how to press the math calculator in technical secondary school) I'm a beginner In the range of 0 · ~ 360 ·, the same angle as 1372.34 'is (accurate to 1) two, 137.53 ≈ (accurate to 0.0001) 19 π / 3 π ≈ (accurate to 1) - 17 π / 8 ≈ (accurate to 1) sin (- 852 ° 17 ') ≈ (accurate to 0.0001) cos1604 ° 12' 33 '≈ (accurate to 0.0001) 6.28 ≈ (accurate to 1) 97.5 ° ≈ (accurate to 0.0001) Tan 796 ° 43' ≈ (accurate to 0.0001) arc Tan 0.3415 ≈ (accurate to 1) if Sina = 0.5427, then angle a ≈ (accurate to 1) If we know sin a = 0.2564. A is the first quadrant angle, then cos a = 0.8502 (accurate to 0.0001). Who can teach me ·It's a student's model, Deli dl-1710

Who can teach me how to press the math calculator in technical secondary school) I'm a beginner In the range of 0 · ~ 360 ·, the same angle as 1372.34 'is (accurate to 1) two, 137.53 ≈ (accurate to 0.0001) 19 π / 3 π ≈ (accurate to 1) - 17 π / 8 ≈ (accurate to 1) sin (- 852 ° 17 ') ≈ (accurate to 0.0001) cos1604 ° 12' 33 '≈ (accurate to 0.0001) 6.28 ≈ (accurate to 1) 97.5 ° ≈ (accurate to 0.0001) Tan 796 ° 43' ≈ (accurate to 0.0001) arc Tan 0.3415 ≈ (accurate to 1) if Sina = 0.5427, then angle a ≈ (accurate to 1) If we know sin a = 0.2564. A is the first quadrant angle, then cos a = 0.8502 (accurate to 0.0001). Who can teach me ·It's a student's model, Deli dl-1710

First of all, I want to tell you that whether you use a calculator or not to convert a large angle to 0 ° to 360 ° or not, you should use the knowledge of the same angle set at the end. For example, the first thing I said is to subtract K from 1372 ° and multiply K by 360 ° (k is a positive number, can be positive, can be negative, can be zero), so that the difference is between 0 and 360

1. If x = 2 + radical 3, find the value of the cubic power of X - 4x & sup2; + 3x + 1
2. Given x = (radical 2 + 1) / 2, find the value of the fourth power of the algebraic formula 4x + the third power of 4x - 9x & sup2; - 2x + 1
3. Simplify (1 + root 3) times (root 3 + root 5), and then divide by (1 + 2 root 3 + root 5)
4. Given a = root 7-1, find the cubic power of 3A + 12a & sup2; - 6a-12

1. 1. We have obtained the value of - 4x & sup2; + 3x + 1 with x = 2 + radical 3
x³-4x²+3x+1= x(x²-4x+3)+1=x(x-1)(x-3)+1=(2+√3)(1+√3)(-1+√3)+1=2(2+√3)+1=5+2√3
2. Given x = (radical 2 + 1) / 2, find the value of the fourth power of the algebraic formula 4x + the third power of 4x - 9x & sup2; - 2x + 1
4x^4+4x³-9x²-2x+1=4x²(x²+x-2)-(x²+2x+1)+2=4x²(x+2)(x-1)-(x+1)²+2
Substituting x into: original formula = (√ 2 + 1) & sup2; (√ 2 + 5) (√ 2-1) / 4 - (√ 2 + 3) & sup2 / / 4 + 2
=（√2+1)（√2+5)/4 - （11+6√2)/4 + 2
=（7+6√2)/4 - （11+6√2)/4 + 8/4
=1
3. Simplify (1 + root 3) times (root 3 + root 5), and then divide by (1 + 2 root 3 + root 5)
（1+√3）（√3+√5）/（1+2√3+√5）
=1/[（1+2√3+√5）/（1+√3）（√3+√5）]
Because: (1 + 2 √ 3 + 5) / (1 + 3) (√ 3 + 5)
=1/（√3+√5）+1/（1+√3）
=（√5-√3）/2 + （√3-1）/2
=（√5-1）/2
So: the original formula = 1 / [(√ 5-1) / 2] = 2 / (√ 5-1) = 2 (√ 5 + 1) / 4 = (√ 5 + 1) / 2
4. Given a = root 7-1, find the cubic power of 3A + 12a & sup2; - 6a-12
3a³+12a²-6a-12
=(3a³+6a²+3a)+(6a²+12a+6)-(21a+21)+3
=3a(a+1)²+6(a+1)²-21(a+1)+3
Substituting a = √ 7-1
Original formula = 21 √ 7-21 + 42-21 √ 7 + 3 = 24

Use 20 beads to place a nine digit number on the counter. What is the maximum and minimum number?

Is it an abacus? The largest 9-digit number is 992000000, and the smallest 9-digit number is 100000199
The maximum is to put the beads as high as possible. Of course, each person can put up to 9 beads, so the maximum is 992000000. The minimum is to ensure that it is 9 digits, put 1 bead on the highest position, and the others can put up as low as possible, so the minimum is 100000199

The concept of factorization of complete square formula

You mean two, three, four The complete square formula of n terms?
In fact, after factorization, the coefficients of each term are the corresponding numbers on Yang Hui's triangle~

The concept of factorization, how is the final result of factorization. Is the final problem into how to complete?

Factorization is to transform a polynomial into the product of several simplest integers
For example:
ax+bx
The factorization is: X (a + b)
Specific visible http://baike.baidu.com/view/19859.htm I can learn it in junior high school
Hope to be useful. Hope to adopt

Is the concept of factorization the same as that of factorization?

Same

1、4、3 2、5、9 3、6、17 4、7、?
What kind of rules should be followed to fill in the place where you want to go

255 8 346 9

Given the vector a = (1, radical 3), B = (- 2,0) 1. Find the angle between A-B and A. 2. When t belongs to [- 1,1], find the value range of {a-tb}

30
[radical 3,3]

If the quadratic radical √ X-2 is meaningful, then the value range of X is

X is greater than or equal to 2

If the quadratic radical √ X-5 is meaningful, then the value range of X is

If 5 is under the root sign, the value range is x greater than or equal to 5
If 5 is not under the root sign, the value range of X is x greater than or equal to 0