Given that x.y satisfies the following conditions: X-Y + 5 ≥ 0; X ≤ 3; X + y + K ≥ 0 and the minimum value of Z = 2x + 4Y is - 6, then the constant k is

Given that x.y satisfies the following conditions: X-Y + 5 ≥ 0; X ≤ 3; X + y + K ≥ 0 and the minimum value of Z = 2x + 4Y is - 6, then the constant k is

Given the fixed points a (- 1,0), B (1,0), point P moves on the circle (x-3) ^ 2 + (y-4) ^ 2 = 4, find the coordinates of point P when | PA | ^ 2 + | Pb | ^ 2 is the minimum
HELP ME!

According to the equation of circle, the coordinates of point P can be set as (3 + 2Sin x, 4 + 2cos x) and (3 + 2Sin x, 4 + 2cos x)
|PA|^2+|PB|^2=60+24SIN X+32COS X=60+4*（6SINX+8COSX）
So the minimum value is 60 + 4 * (- 10) = 20. You also know that the value of SiNx and cosx can be found out when the coordinates are set back

The area of a square is 10 square centimeters. How much is its side length? What is the key point

Let the side length of a square be X
x*x=10 x=5
4 * 5 = 20 cm

Find a point P on the ellipse x ^ 2 / 25 + y ^ 2 / 16 = 1 to minimize the distance from it to the straight line 4x + 3Y + 36 = 0, and find the minimum value

The equation of ellipse is written as parameter equation, which is x = 5cosq, y = 4sinq
Let P (5cosq, 4sinq)
According to the formula of distance from point to line, d = | 20cosq + 12sinq + 36 | / 5 > = (36-4 radical 34) / 5
The minimum value is (36-4 radical 34) / 5

How many centimeters is the side length of a square with an area of 10 square centimeters?

Root ten

If point P is the point on the ellipse 25X ^ 2 + 9y ^ 2 = 255 and is the two focal points of the ellipse, then the value of ∣ Pf1 ∣ + ∣ PF2 ∣ is:

25X^2+9y^2=255
x²/(51/5)+y²/(85/3)=1
∣ Pf1 ∣ + ∣ PF2 ∣ = double root 85 / 3 = 2 √ 255 / 3

The side length of the square is 20 cm, the area of the painted part
There is a circle in the square, the rest is not painted
There are four circles in the square. There are no colors in other places
There are 16 circles in the square, and the rest are not painted
Please hurry up! School is going to start! Before the day after tomorrow is OK!

The area is the same, 100 π cm and 178;

The range of ellipse 4x + y square = 16. X square + 4Y square = 16 find the major axis, minor axis, eccentricity, focus coordinates and vertex coordinates
Ask prawn to instruct. Just learned ellipse

I didn't understand the first sentence
From the second sentence:
x²/16+y²/4 = 1
a = 4 , b = 2 , c= 2√3
The major axis is 8 and the minor axis is 4
Eccentricity e = C / a = root 3 / 2
Focus coordinates (- 2 √ 3,0), (2 √ 3,0)
Vertex coordinates (4,0), (- 4,0), (0,2), (0, - 2)
I don't know if the explanation is clear

The area of a square is 10 square centimeters. How many square centimeters is the area of the painted part?

14 × 10 × 34, = 23.55 (square centimeter); a: the area of shadow is 23.55 square centimeter

Find the length, eccentricity, vertex and focus coordinates of the major axis and minor axis of the following ellipses, 16x square + y square = 25

Divide the two sides by 25
x²/(5/4)²+y²/5²=1
So a & # 178; = 5 & # 178;, B & # 178; = (5 / 4) &# 178;
So a = 5, B = 5 / 4
c²=a²-b²=375/16
So long axis 2A = 10
Minor axis 2B = 5 / 2
e=c/a=√15/4
Vertex (± 5 / 4,0), (0, ± 5)
Focus (0, ± 5 √ 15 / 4)