The calculus of function y = x & sup3; dy =?

The calculus of function y = x & sup3; dy =?

The calculus of y = x & # 179; dy = 3x & # 178; DX

The geometric meaning of derivative is the slope somewhere?

The derivative of F (x) at x0 = [f (x0 + Δ x) - f (x0)] / Δ x
When Δ x tends to zero, it means the derivative of F (x) at x0

The geometric meaning of the first derivative is slope. What is the geometric meaning of the second derivative?
Y '= x (x-1) stable point 0,1 why is y' '(0) = - 1 = 0 maximal? What does it mean?

The second derivative has no special geometric meaning. Usually, according to the sign change of the second derivative, we can judge the concavity and convexity and inflection point of the function curve, or judge whether the stationary point is the extreme point and obtain the maximum or minimum
In the example, y '' (0) = - 1 = 0 indicates that f (0) is minimal
On the other hand, your minimax are wrong

The distance between a and B is 40 km, the speed of motorcycle is 45 km / h, and the speed of freight car is 35 km / h
1. If two vehicles travel from two places in the same direction at the same time, after a few hours, the distance between the two vehicles is 20 km?
2. If the motorcycle is in place a and the truck is in place B, the two vehicles are facing each other at the same time, and there is a traffic jam due to too many vehicles when they meet. The motorcycle has to find another way to place B. the truck can only get home along the original road, and the truck can only arrive in place a 10 minutes after the motorcycle arrives in place a?

1. (40-20) / (45 + 35) = 0.25 hours or (40 + 20) / (45 + 35) = 0.75 hours, 2,10 minutes = 1 / 6 hours, 22 minutes = 11 / 30 hours. When the truck meets, it takes 40 / (45 + 35) × 35 = 17.5 kilometers for the truck to return to Jiadi, 17.5 / (35 + 11 / 30 = 26 / 30 = 13 / 15 hours

Given that the solution of the equation AX + B = C about X is x = 1, find the value of | c-a-b-1 |

According to known, substituting x = 1 into the equation AX + B = C, we can get a + B = C, that is, C-A-B = 0, so | c-a-b-1 | = | 0-1 | = 1

Two cars leave from A. B at the same time. Car a travels 50 kilometers per hour and car B 40 kilometers per hour. The two cars meet at 20 kilometers from the midpoint of A. B. find the meeting time

The two cars meet at a distance of 20 km from the midpoint, that is, the distance difference between the two cars is 40 km
Encounter time = 40 / (50-40) = 4 hours

When Xiao Ming solved the equation 2x-3 / 5 + 1 = x + A / 2, he forgot to multiply 1 on the left side of the equation by 10 to get x = 0, to find a and the solution of the real equation

2x-3/5+1=x+a/2
X = 0, substituting 0-3 / 5 + 1 = A / 2, a = 4 / 5
2x-3/5+1*10=x+2/5
x=-9

Party A and Party B set out from two places 225 kilometers apart and walked towards each other at the same time. It is known that the speed ratio of Party A and Party B is 10:7. How many kilometers did they walk when they met?

1. Speed A: speed B = 10:7; distance a: distance b = 10:7
2. A: 225 △ (10 + 7) × 10 = 2250 / 17 (km)
3. Route B: 225 △ (10 + 7) × 7 = 1575 / 17 (km)

The decimal point of a decimal is moved one place to the left, and the number obtained is 2.52 less than the original number. This decimal is______ ．

2.52 ÷ (1-110), = 2.52 ÷ 910, = 2.8; answer: the decimal is 2.8, so the answer is: 2.8

Party A and Party B are 750 km apart. How many hours can the two cars meet after the two cars are 450 km apart three hours apart

Speed sum of two cars = (750-450) △ 3 = 100 (km)
How many more hours: 450 △ 100 = 4.5 (hours)
A: the two cars can't meet until they travel another 4.5 hours