If the function f (x) is defined on [a, b] and | f (x) | is integrable on [a, b], does the integral of F (x) exist on [a, b]?

If the function f (x) is defined on [a, b] and | f (x) | is integrable on [a, b], does the integral of F (x) exist on [a, b]?

If the function f (x) is continuous on [a, b], then f (x) is integrable on [A.B]. Let f (x) = 1 (x ≥ 0), - 1 (x < 0) (a piecewise function form), then f (x) is not a continuous function, but | f (x) | = 1 is a continuous function, so f (x) is not necessarily integrable

According to the number of factors, natural numbers can be divided into prime numbers, composite numbers and one or three parts. Why?

If the natural number includes 0, this sentence is wrong, because 0 is neither prime nor composite nor 1

F (x) = 2 ^ 2x-5 / 2 * 2 ^ x + 1-6, X belongs to [0,3]. Find the maximum value of F (x)

If f (x) = (2x-5) x ^ (2 / 3) is derived, then f (x) = 10 / 3 [x ^ (2 / 3) - x ^ (- 1 / 3)], let it = 0, then x = 1, so f (x) = (2x-5) x ^ (2 / 3) has an extreme value - 3 at x = 1, because f (x) = 10 / 3 [x ^ (2 / 3) - x ^ (- 1 / 3)] is further derived as f (x) = 10 / 3 [(2 / 3) * x ^ (- 1 / 3) + 1 / 3x x ^ (- 2 / 3)] is greater than 0 at x = 1

1. The ratio of a and B is 5:3, the difference is 12, and B is ()
2. Solving equation: 19-20% x = 7 (with process)
3. Solving equation: 4 / 9: 1 / 6 = x: 15 (with process)

1. The ratio of a and B is 5:3, the difference is 12, and B is (18)
2. Solving equation: 19-20% x = 7 (with process)
0.2X=19-7
0.2X=12
X=60
3. Solving equation: 4 / 9: 1 / 6 = x: 15 (with process)
8：3=X：15
3X=8*15
3X=120
X=40

First line 1, second line 234, third line 56789. Sum of line n

The last number in line n = n & # 178;,; the first number = (n-1) & # 178; + 1, the number of common terms: n & # 178; - [(n-1) & # 178; + 1] + 1 = 2N-1, the sum s = & # 189; [(n-1) & # 178; + 1 + n & # 178;] × (2n-1) = 2n & # 179; - 3N & # 178; + 3n-1

Is o an integer? Must natural numbers be integers? Must 0 be positive integers? Must integers be natural numbers? I am poor in mathematics

O is an integer
Natural numbers must be integers
0 is not a positive integer
Integers are not necessarily natural numbers

Math answers to the third grade summer homework
Party A, Party B and Party C bought 8 kg of fruit together and divided it into three parts evenly. Each person has one share. Party A pays 5 kg of fruit, Party B pays 3 kg of fruit. After that, Party C should pay 3.2 yuan to Party A and Party B, and give it back to Party A and Party B. how much should Party A and Party B pay?

C took out 3.2 yuan, indicating that each person should pay 3.2 yuan, a total of 3.2 × 3 = 9.6 yuan
8 kg of fruit is 9.6 yuan, 1 kg is 9.6 △ 8 = 1.2 yuan,
Party A pays 5 kg of fruit, 5 × 1.2-3.2 = 2.8 yuan more
B paid 3 kg of fruit, 3 × 1.2-3.2 = 0.4 yuan
A should be 2.8 yuan, B should be 0.4 yuan

Proof: the sum of three continuous natural numbers must be divisible by 3

Let the natural number in the middle be n, then the two outer numbers are n-1 and N + 1
n-1+n+n+1=3n
So the sum of three continuous natural numbers must be divisible by 3

The value of cubic root-a Square-1 must be
Positive number negative number non positive number non negative number

-a²≤0
So - a-178; - 1

There is a batch of goods in the warehouse. One fifth of the goods were transported in the first day, and eight tons more in the second day than in the first day, leaving 14 / 25 of the total weight of the goods,
How many tons are the goods?

x*1/5+8+x*1/5+14/25*x=x
x=200