The first partial derivative of Z = Y / F (x2-y2)

The first partial derivative of Z = Y / F (x2-y2)

ðz/ðx=-yf'(x^2-y^2)*2x/[f(x^2-y^2)]^2=-2xyf'(x^2-y^2)*/[f(x^2-y^2)]^2ðz/ðy=[f(x^2-y^2)-yf'(x^2-y^2)*(-2y)]/[f(x^2-y^2)]^2=[f(x^2-y^2)+2y^2*f'(x^2-y^2)*]/[f(x^2-y^2)]^2

X2 + Y2 + Z2 = XY + YZ + ZX find the value of [x-zy + Z] to the power of 2010

X & sup2; + Y & sup2; + Z & sup2; = XY + YZ + zxx & sup2; + Y & sup2; + Z & sup2; - xy-yz-xz = 0 multiply by 22x & sup2; + 2Y & sup2; + 2Z & sup2; - 2xy-2yz-2xz = 0 (X & sup2; - 2XY + Y & sup2;) + (Y & sup2; - 2yz + Z & sup2;) + (Z & sup2; - 2XZ + X & sup2;) = 0 (X-Y) & sup2; + (Y-Z) & su

(Grade 6) there are two piles of apples. If one fifth of them are taken out of pile a and put into pile B, there will be as many apples in the two piles. How many apples in pile B are in pile a

Let there be apples in the pile and X in the pile,
Then a left Apple x-x / 5 = 4x / 5
Then B has Apple x-x / 5-x / 5 = 3x / 5
So 3x / 5 / x = 3 / 5

Is the mean inequality the basic inequality?

Different mean inequality has a wider range of applications. Mean inequality includes harmonic mean, geometric mean, arithmetic mean and square mean

A and B two cars from AB two opposite, meet after driving 5 hours, B car arrived at a, a car more than B 90km, more than 25% of the whole journey, find a car speed

Vehicle a is 90km over B, more than 25% of the whole journey
The whole process is equal to 90 / 25% = 360
The distance between the two cars is ab + 90
That is, 360 + 90 = 450, the sum of two vehicle speeds is 450 / 5 = 90
Then we drove 360 / 90 = 4 hours before meeting
A total of 4 + 5 = 9 hours, 360 + 90 = 450 meters
His speed is 450 / 9 = 50

What is the solution set of inequality x plus X-2 which is greater than zero

(x-2)/(x+3)>0
That is, (X-2) (x + 3) > 0
So x > 2, or X

A passenger car and a freight car leave from a and B at the same time. After meeting for 2.5 hours, the passenger car travels 40 kilometers more than the freight car. It is known that the passenger car travels 82 kilometers per hour. How many kilometers can the freight car travel per hour

Bus travel distance: 82 * 2.5 = 205
Truck travel distance: 205-40 = 165
Vehicle speed: 165 / 2.5 = 66

Let a = {2a-1 |, 2}, B = {2,3, A2 + 2a-3} and ∁ Ba = {5}, then the value of real number a is______ ．

Because ∁ Ba = {5}, so | 2a-1 | = 3 and A2 + 2a-3 = 5, that is, A2 + 2a-8 = 0, a = 2 or a = - 1 is obtained from ふ 2a-1 | = 3, and a = 2 or a = - 4 is obtained from A2 + 2a-8 = 0, so a = 2 satisfies the condition

3 / 5 of a is equal to 5 / 8 of B. what is a part of B?
The wrong number is two fifths

A is 5 / 8 of B △ 2 / 5 = 25 / 16

How many natural numbers less than 2000 can be formed with the number 0 1 2 3 4?

Single digit, ten digit and hundred digit can be taken as: 0,1,2,3,4 (5 digits)
Thousand digits can be taken as 0,1 (2 digits)
So a total of 5 * 5 * 5 * 2 = 250 can be formed