We know the square of the equation X-2 (M + 1) x + m about X 1. When m takes what value, the equation has two equal real roots? 2. Choose a suitable integer for m, so that the equation has two unequal real roots, and find out the two roots. Solving process and replacement method

We know the square of the equation X-2 (M + 1) x + m about X 1. When m takes what value, the equation has two equal real roots? 2. Choose a suitable integer for m, so that the equation has two unequal real roots, and find out the two roots. Solving process and replacement method

Because the equation has two equal real roots, it has: B & # 178; - 4ac = 0;
【-2（m+1）】²-4*1*m²=0；
4m²+8m+4-4m²=0
8m+4=0；m=-1/2；
If there are two unequal real roots of the equation: B & # 178; - 4ac > 0, then there are:
B & # 178; - 4ac = 8m + 4 ﹥ 0; if M chooses an integer at will, then B & # 178; - 4ac = 8m + 4 can be completely squared
If M is taken as 4, then there is:
8 * 4 + 4 = 32 + 4 = 36; 36 can be completely squared
X1 = (- B + radical B & #178; - 4ac) / 2A = - [[- 2 (M + 1)] + radical 36] / 2 * 1;
=（10+6）/2
=8；
X2 = (- b-radical B & # 178; - 4ac) / 2A = - [[- 2 (M + 1)] - radical 36] / 2 * 1;
=(10-6)/2;
=1；

The area of an isosceles right triangle is 9 square meters. Take the right side of an isosceles triangle as the radius to draw a circle. What is the area of this circle?

Let the right edge be X,
X squared by 2 = 9
So x squared equals 18
The area of a circle is x squared times π
So the area of the circle is 18 π

Given the point (half, 2) on the image of function y = (2k-1) x, find the value of K and the analytic expression of function, and draw the image of function

X = ½, y = 2 into y = (2k-1) x
We get 2 = - 189; (2k-1)
k=2.5
y=4x
x=0,y=0
After (0,0), ((189;, 2), drawing a straight line is an image

Let z = f (x + y, XY) and F have the second order continuous partial derivative, then find zxx and ZXY

As shown in the figure, it is a pattern made of pieces. The first pattern needs seven pieces, the second pattern needs 19 pieces, and the third pattern needs 37 pieces. How many pieces do you need to place the nth pattern in this way?

Take the first pattern as one layer: 7, the second, two layers: 7 + 12 = 7 + 6x2, the third, three layers: 7 + 12 + 18 = 7 + 6x2 + 6x3 = 7 + 6X5, the fourth, four layers: 7 + 12 + 18 + 24 = 7 + 6x2 + 6x3 + 6x4 = 7 + 6x9 The nth, n-layer: 7 + 6x (n + 2) (n-1) / 2 = 7 + 3 (n + 2) (n-1) n ≥ 2 the 100th, 100 layers, 7 +

On the third day of this year, I had a lot of trouble in doing mathematical geometry problems, especially the combination of number and shape of quadratic function, and moving point problems,

If I remember correctly, I will mainly do the training of these topics in the next half year
There are also basic steps to seek in practice
And these topics are of little use to high school and beyond
That is, it is difficult to improve oneself from a higher perspective
Geometry problem is a complete quadratic, which is a point formula

The vertex coordinates of quadratic function y = (x-1) square + 2 are

（1,2）

If a and B are integers and ab = 24, then the minimum value of a + B is ()
A. 10B. -11C. -12D. -25

∵ 24 = 1 × 24 = 2 × 12 = 3 × 8 = 4 × 6 = (- 1) × (- 24) = (- 2) × (- 12) = (- 3) × (- 8) = (- 4) × (- 6), ∵ when a and B are decomposed into - 1 and - 24, the value of a + B is the minimum, and the minimum value is: (- 1) + (- 24) = - 25

In the triangle ABC, ab = AC, BC = BD, ad = de = EB, points D and E are on AC and ab

Because: ad = de
So:

How many square kilometers is 200 hectares? How many square decimeters is 4 square meters and 40 square decimeters?
How many square kilometers is 200 hectares?
4 square meters 40 square decimeters equal to how many square decimeters?

0.2 square kilometers