Math problems about the concept of dichotomy!! I don t understand the answer!!

In the first sentence, according to the dichotomy step, as long as there is a zero point in a given interval, it must be solved. The first sentence contains a layer of meaning: it is possible that there is a zero point in the interval and it is not possible to find it by the dichotomous method, which is a mistake.

The reason for the error on the second floor is that the dichotomy requires that f(a) and f(b) have different signs. It is true that the dichotomy can only proceed in the case of f(a) with f(b) heterogeneity, but this is not the real reason for the error in the first sentence. In fact, if you can't first ensure that f(a)*f(b)<0 is 0, it can't be called a dichotomy.

The dichotomy itself is divided into multiple steps, in the first step, it has been ensured that the input a,b can satisfy the conditions of f(a)*f(b)<0, if the entered values of a and b do not meet the conditions, the dichotomy program will require re-entry of a,b until the conditions are met, and then move on to the next step of the dichotomy. Therefore, the dichotomy must be able to find the existence of zero points in the specified interval and never miss it.

The second sentence is understood on two levels. At the first level, the meaning expressed is the same as in the first sentence. At the second level, whether there is a zero point or not in a function is objective, and does not depend on the specific solution method, and will not lead to the difference in the existence of the zero point because of the different solution methods.

From this two-level analysis, this sentence is also wrong.

The approximate solution of the dichotomous equation requires f(a) and f(b) signs.

Go your back.

The total speed is 8 km/h + 6 km/h = 14 km/h.

Because it took 4 hours to walk, the total distance covered was 14 4 = 56 km.

Add in the 10 kilometers that would have been apart, and it will be 66 kilometers.

6+8=14km/h

14×4=56km

56+10=66km

The distance between the two villages in the west is = Liyun + Jiahui + the original two people are 10 kilometers away Liyun walked: 6 times 4 = 24 km, indicating that Liyun walked 24 km Jiahui walked: 8 times 4 = 32 km, indicating that Jiahui walked 32 km So:

Liyun + Jiahui + the original distance between the two is 10 kilometers = 24 + 32 + 10 = 66 (kilometers).

A: The distance between the two villages in the west is 66 kilometers.

Solution: Jiahui and Liyun travel 14 kilometers per hour, 4 hours 14 * 4 = 56 kilometers, the distance between the east and west villages is 10 kilometers at the beginning of the opening and the sum of the distance between the two people walking 56 + 10 = 66 (kilometers).

4 hours later, Jiahui walked 4x8 kilometers, Liyun walked 4x6 kilometers, plus the distance between the two of them was 10 miles, and the east and west villages were far apart.

4*8+4*6+10=66 km.

The total distance traveled by two people in 4 hours is 4 (8+6)=4 14=56 km.

The distance between the east and west villages is 56 + 10 = 66 kilometers.

When x is -3, substitute the equation, the result is greater than 0, so go to the number -2 larger than -3 to bring in the equation, and the solution of the spring and Ming x = -2 when y is less than zero, so the selection, the shed pin is brought in again, smaller than the big pickpocket, and so on. When it is close to 0, it is the solution. When in doubt, ** me.

When x is the root number 5 of the negative Zen confront, it is the negative zero He Han family point, (-root number 5,0) (0) If it is accurate, (,0) old eggplant.

Dichotomy is a kind of approximation method to solve mathematical equation problems, which mainly narrows the range step by step to approximate the solution of the equation.

The theoretical basis is the continuity of the equation curve.

General steps: 1. First, determine the value of the equation at a certain two points, such as a and b, where f(a) > 0 and f(b) < 0. Let's assume a)2, that is, take the midpoint, that is, the value at (a+b) 2, and see if it is greater than 0 or less than 0Then just keep repeating this until you can identify a solution that meets your needs.

That's the wrong question. There are y meters of steel pipes.

Let there be x1 roots when divided into 6 minutes, and x1 is a positive integer. 6*x1+。

Let it be divided into 8 points with x2 roots and x2 positive integers. 8*。

Simultaneous two formulas, eliminating y yields 8*x2-6*x1=, x2 is a positive integer, then 8*x2 and 6*x1 are positive integers. Subtracting two positive integers, it is impossible to equal a decimal number. So the title is wrong.

The difference between section 6 and section 8: m) length of each section: m) length of this steel pipe: m)

！Let the total length of the steel pipe be x, (x%6) -x%8) + and you will be, right? Find x. It's just a result of both sides of the equation.

Solution: Let this steel pipe be x meters.

6x+6x-8x=

2x=x=

Long meters.

I didn't think of how to write the equation -.-