I am proud that I am Chinese I am Chinese - the Loess Plateau is my chest, the Yellow River is my blood, the Great Wall is my arm, and Mount Tai is my heel. "It must be wonderful!

I am proud that I am Chinese I am Chinese - the Loess Plateau is my chest, the Yellow River is my blood, the Great Wall is my arm, and Mount Tai is my heel. "It must be wonderful!

I'm Chinese - my ancestors came out of the forest first, and my ancestors began to work first. I'm the descendant of compass and printing. I'm the descendant of PI and seismograph. I'm Chinese - in my nation, there are not only immortal Confucius, Sima Qian, Li Zicheng

If the inverse scale function y = K / x, when x is less than 0, y decreases with the increase of X. which quadrant does the image of the first-order function y = K (x-k) not pass?

Second quadrant

Partial derivative. Urgent
Let z = (e ^ u) SINV and u = XY, v = x + y find DZ / DX, DZ / dy

DZ / DX is the partial derivative of Z to X. in this way, if u and V are brought in, the direct spherical partial derivative is good
dz/dx=y*e^(xy)*sin(x+y)+e^(xy)*cos(x+y)
The same can be obtained
dz/dy=x*e^(xy)*sin(x+y)+e^(xy)*cos(x+y)

A test, a.b.c.d four results are as follows: A.B.C average: 91 points, b.c.d average: 89 points, A.D average: so, a got more
The results of a.b.c.d are as follows:
A. B.C. average: 91
B. C.D. average: 89
A. D average score:
So, how much did a get

A + B + C = 91 * 3 (1)
B + C + D = 89 * 3 (2)
From formula (1) - (2), we can get
A - D = 2 * 3 (3)
Again by
A + D = 95 * 2 (4)
In combination with (3) (4), it is concluded that
A =98

In quadratic function, how to use formula method to transform general form into vertex form

How to use and match

How to solve this equation 5.5 + 0.4 * 11 = 11x

5.5+4.4=11x
9.9=11x
x=9.9/11
x=0.9

If a + B / AB = 3, find the algebraic formula 2A + 2B AB / A + B + 2Ab
How to write it

a+b=3ab
2a+2b-ab=6ab-ab=5ab
a+b+2ab=5ab
So the original formula is 1

If the radius of the inscribed circle of △ ABC is R and the perimeter of △ ABC is l, then the area of △ ABC is___ ．

As shown in the figure, connect OE, OD, of; OA, ob, OC; then OE ⊥ AB, of ⊥ AC, OD ⊥ BC; s △ ABC = 12ab × OE + 12bc × od + 12ac × of ∵ OE = of = od = R, AB + BC + AC = L, ∵ s △ ABC = 12ab × R + 12bc × R + 12ac × r = 12R (AB + BC + AC) = 12rl

How many meters is one foot?

One foot is ten feet, three and a third of a meter

The school playground is 220 meters long and 80 meters wide. After trimming, the length is reduced by 10 meters and the width is reduced by 10 meters. How about the area of the playground after trimming?
Whether the area after trimming is larger or smaller than the original one remains unchanged

14700 square meters smaller than before