Use a poem or two to describe or praise the scenery below soft spring rain: Willow: Plum blossom:

Use a poem or two to describe or praise the scenery below soft spring rain: Willow: Plum blossom:

Spring rain: with the wind into the night, moisten things silently
Willow: I don't know who cut out the fine leaves. The spring breeze in February is like scissors
Plum blossom: in the deep snow in front of the village, it bloomed last night

Please answer the riddle in detail, thank you! (17:18:19:10)
Some are rugged, some are not good at traveling, and some are not good at traveling
Connecting half, breaking half, connecting or breaking
One Yin and one Yang, one short and one long, one day and one night, one hot and one cool
 

1. Skin
2. Discount
3. Ming Dynasty

1. Known 2 ≤ X

2≤x

Given the moving point m (x, y), vector M = (x-3, y), n = (x + 3, y), and satisfying m + n = 8, then the trajectory equation of the moving point P is obtained

M + n = 8, i.e
√[(x-3)²+y²]+√[(x+3)²+y²]=8
Let F1 (- 3,0), F2 (3,0), P (x, y)
So | Pf1 | + | PF2 | = 8
So the trajectory of P is an ellipse with F 1 and F 2 as focus and 8 as major axis
So a = 4, C = 3, B & # 178; = A & # 178; - C & # 178; = 7
The equation is X & # 178 / 16 + Y & # 178 / 7 = 1

If the diameter AE of circle O is 20cm, the chord BC is 16cm and BC ⊥ AE is D, then the area of triangle ABC?
1. Please write the process
2. The answer is double solutions

How to say, it's too simple. If R is 10 and BD is 8, then od is 6. In two cases, a is on the left side and right side of BC (it may be on the upper or lower side according to the drawing), ad = r-od = 4, s = 4 * 16 / 2 = 32 on the left side, ad = R + od = 16, s = 16 * 16 / 2 = 128 on the right side

Factorization: 81a quartic-3a cubic

81a^4-3a^3=a^3(81a-3)=3a^3(27a-1)

The following equations are given: 1) P = 2cos θ; 2) P = - 3sin θ; 3) P = 1; 4) PSIN θ = - 2; 5) PCOS θ = 1; 6) P = sin θ - root sign 3cos θ. Among them, how many equations are used to represent a circle? Why?

If the equation of circle is 1,2,3,6p = (x ^ 2 + y ^ 2) ^ 0.5, sin θ = Y / (x ^ 2 + y ^ 2) ^ 0.5, cos θ = x / (x ^ 2 + y ^ 2) ^ 0.5, then the above equation is transformed into the equation in rectangular coordinate system as 1. X ^ 2 + y ^ 2-2x = 02. X ^ 2 + y ^ 2 + 3Y = 03. X ^ 2 + y ^ 2 = 14. Y = - 25. X = 16. X ^ 2 + y ^ 2 + 3 ^ 0.5x-y = 0

As shown in the figure, in △ ABC, D is the point on AB, and ad = AC, AE ⊥ CD, the perpendicular foot is e, and F is the midpoint of CB

Prove: in △ ACD, because ad = AC and AE ⊥ CD, according to the intersection point of the vertical line and the bottom of the isosceles triangle, we can prove that e is the midpoint of CD, and because f is the midpoint of CB, so EF ∥ BD, and EF is the median line of △ BCD, so EF = 12bd, that is BD = 2ef

How many cubic meters is a liter?

1L=1dm^3=0.001m^3

If log0.2x > 0 (with 0.2 as the base), then the value range of X is? Logx3

In this case, it will become LGB / LGA. Corresponding to your question, it is lgx & gt; 0. So x & gt; 1. & nbsp; the next one is lgx & lt; 0, combined with the definition field of X (from zero to positive infinity), so 0 & lt; X & lt; 1