If the equation x2 + y2-2ax + 4ay + 6a2-a = 0 represents a circle whose center is in the fourth quadrant, then the range of real number a is______ ．

If the equation x2 + y2-2ax + 4ay + 6a2-a = 0 represents a circle whose center is in the fourth quadrant, then the range of real number a is______ ．

The equation x2 + y2-2ax + 4ay + 6a2-a = 0 is transformed into the standard equation as follows: (x-a) 2 + (y + 2a) 2 = A-A2, and its center coordinates are (a, - 2A). If the equation (x-a) 2 + (y + 2a) 2 = A-A2 represents the circle with the center in the fourth quadrant 〈 a − A2 ＞ 0A ＞ 0 − 2A ＜ 0 〉 a ＜ 1, the answer is: 0 ＜ a ＜ 1

Proof: the equation (k-1) x + 2 √￣ 2kx + 2 = 0 of X has constant and real roots, which is the double root sign multiplied by KX

Use discriminant! B2-4ac to prove constant greater than 0! Very simple!

What is the circumference of a square with a side length of 6 cm______ If the perimeter of another rectangle with a length of 8 cm is equal to the perimeter of this square, then the width of the rectangle is______ Cm

6 × 4 = 24 (CM), 24 △ 2-8, = 12-8, = 4 (CM), answer: the perimeter of a square is 24 cm, and the width of a rectangle is 4 cm

(the height of the column is 3 meters, and the perimeter of the bottom surface is 3.14 meters.) paint five such columns with 0.5 kg of paint per square meter. How many kg of paint do you need?

Hello
Paint area per column
3.14 × 3 = 9.42 (M2)
Paint area of 5 columns
5 × 9.42 = 47.1 (M2)
All in all, we need paint
47.1 × 0.5 = 23.55 (kg)

How to use calculator
How to calculate variance and standard deviation with Casio scientific calculator
fast

First press mode to select SD to enter statistics
Input data one by one, press M+
After input, press shift 2 (the Yellow symbol above 2 represents variance) and other symbols. You can use the average to calculate everything
Also remember to shift AC to clear memory data for new statistics
Specific operation to see the most reliable manual

Differential problems of higher numbers, x = 1 + T ^ 2, y = cos t d ^ 2Y / D ^ 2x = ()

dy/dx=dy/dt/dx/dt=-sint/2t,d^2y/dx^2=(dy/dx)/dt/dx/dt=(-2tcost+2sint)/8t^3

If a, B are reciprocal and C, D are opposite, then the power of 3ab-5 (c + D) is 2012=____

From the meaning of the title:
a×b=1
c+d=0
So:
simple form
=3 × 1-5 × 0 to the power of 2012
=3-5×0
=3

The four numbers 1555 are added, subtracted, multiplied and divided, and the answer is 24
The answer to these four numbers is 24

Can you change your four numbers? This way: 5 × (5 - 1 △ 5) = 24

Let Y1 = a ^ (3x + 1), y2 = a ^ (- 2x), where a > 0 and a ≠ 1, when a is what value
A.y1=y2
B.y1>y2

A.y1=y2
a^(3X+1)=a^(-2X)
3x+1=-2x
x=-1/5
B.y1>y2
When 0

A round fountain is 20cm in diameter. Now we need to build a 1m wide path around the fountain. What is the floor area of the path
Where did 1.1 and 0.1 come from

Radius = 20 / 2 = 10 cm = 0.1 M
The radius of the circle formed by the path is 0.1 + 1 = 1.1m
Lane area = 1.1x1.1x3.14-0.1x0.1x3.14
=3.14x1.2
=3.768 square meters
The road covers an area of 3.768 square meters