Write an essay in English about 100 words by the world famous writer Andersen

Hans Christian Andersen was born in the town of Odense, Denmark, on Tuesday, April 21805. He was an only child. "Hans" and "Christian" are traditional Danish names

Talk about the time Andersen lived in and write two or three other classic fairy tales
Can you write seriously and sincerely?

Andersen is a famous Danish fairy tale writer in the 19th century and the founder of world literature fairy tales. He was born in a poor shoemaker family in Odense. In his early years, he studied in charity school and worked as an apprentice. Influenced by his father and folk oral literature, he loved literature since childhood. At the age of 11, his father died and his mother remarried. In pursuit of art, he came to Copenhagen alone at the age of 14
The emperor's new dress
Flying Box
ugly duckling
The daughter of the sea

The partial terms AK1, ak2, ak3 of the arithmetic sequence {an} with non-zero tolerance If K1 = 1, K2 = 2, K3 = 6, then K4=______ ．

Let the tolerance of the arithmetic sequence {an} be D, ∵ A1, A2, A6 be the arithmetic sequence, ∵ A22 = A1 · A6, that is, (a1 + D) 2 = A1 · (a1 + 5d), ∵ d = 3A1. ∵ A2 = 4A1, ∵ arithmetic sequence AK1, ak2, ak3 And ak4 = a1 + (k4-1) · d = a1 + (k4-1)

Make the following sentences plural
For example, the boy is lazy
1：That girl is very beautiful.------________ .
2:He is an engineer.-----_ .
3:Is she a doctor?------- .
4:This is not my umbrella.-----__________ .

1. Those girls are very beautiful. 2. They are engineers. 3. Are they doctors? 4. They are not my umbrellas

Vertex formula of parabola y = - 3x ^ 2-bx + 1

y=-3x^2-bx+1=-3（x^2 + bx/3 + b^2/36） + 1 + b^2/12=-3(x+b/6)^2 + 1 + b^2/12

A counterexample is given to show that the proposition "two triangles with equal perimeter and area are congruent" is a false proposition
emergency

The height of an isosceles triangle with 3.6 as the base and 4.2 as the waist d = √ (4.2 & sup2; - 1.8 & sup2;) = √ 14.4 = 6 √ 10 / 5 ＞ 3.6, so the area of the triangle is larger than 6

Let a be a real number, and let f (x) = a √ (1-x ^ 2) + √ (1 + x) + √ (1-x) have the maximum value of G (a)
(1) Let t = √ (1 + x) + √ (1-x), find the value range of T, and express f (x) as the function m (T) of T
(2) Find g (a)

(1) In order to make √ (1 + x) + √ (1-x) meaningful, then x ∈ [- 1,1] t ^ 2 = 1 + X + 1-x + 2 √ (1-x ^ 2) = 2-2 √ (1-x ^ 2), so T ^ 2 ∈ [0,2], and T = √ (1 + x) + √ (1-x) > 0, t ∈ [0, √ 2] can be obtained from T ^ 2 = 1 + X + 1-x + 2 √ (1-x ^ 2) = 2-2 √ (1-x ^ 2), then √ (1-x ^ 2) = 1-T ^ 2 / 2, so f

Factorization
1.-1+y+20y^2
2.(x^2-3x-5)(x^2-3x+2)+6
3.(x+1)(x+3)(x+5)(x+7)+15

1.-1+y+20y^2=(4y+1)(5y-1)2.(x^2-3x-5)(x^2-3x+2)+6=(x^2-3x-5)^2+7(x^2-3x-5)+6=(x^2-3x-5+1)(x^2-3x-5+6)=(x^2-3x-4)(x^2-3x+1)=(x^2-3x+1)(x+1)(x-4)3.(x+1)(x+3)(x+5)(x+7)+15 = (x^2+8x+7)(x^2+8x+15)+15 =(x^...

Given that the image of quadratic function passes through point a (- 1,0) C (0,3), and the distance from vertex to X is 4, the analytic expression of function is obtained

Let the function be y = ax ^ 2 + BX + C
Substituting a and B will get
a-b+c=0
c=3
a-b=-3
The y value of vertex coordinates is 4ac-b ^ 2 / 4A
Because the distance from the vertex to X is 4
So 4ac-b ^ 2 / 4A = plus or minus 4
When 4ac-b ^ 2 / 4A = 4
12a-b^2=16a
b^2=-4a
(a+3)^2+4a=0
a^2+10a+9=0
(a+1)(a+9)=0
a=-1,a=-9
b=2 b=-6
When 4ac-b ^ 2 / 4A = - 4
12a-b^2=-16a
b^2=28a
(a+3)^2-28a=0
a^2-22a+9=0
a=11+4√7 a=11-4√7
b=14+4√7 b=14-4√7
So the analytic expression of the function is
y=-x^2+2x+3
y=-9x^2-6x+3
y=(11+4 √7)x^2+(14+4√7)x+3
y=(11-4 √7)x^2+(14-4√7)x+3

When a is equal to, the result of the following formula is 0? (42-6a) divided by 6
The best equation

From the meaning of the title
(42-6a) divided by 6 = 0
Namely
(42-6a) = 0
6a=42
a=7
I wish you progress in your study

Write an essay in English about 100 words by the world famous writer Andersen