The sum of two prime numbers is 40. What is the maximum product of the two prime numbers?

The sum of two prime numbers is 40. What is the maximum product of the two prime numbers?

Prime numbers less than 40 are: 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, of which the sum of two prime numbers is 40 is 3 and 37; 11 and 29, 17 and 23, their products are: 3 × 37 = 111; 11 × 29 = 319; 17 × 23 = 391; a: the maximum product of these two prime numbers is: 391

The sum of two prime numbers is 60. What is the maximum product of these two prime numbers?

29×31=899
A: the two prime numbers are 29 and 31 respectively, and the product is 899
Remember: to maximize the product, you must minimize the difference between the two numbers!

If the sum of two prime numbers is 60, what is the maximum value of the product of the two prime numbers

The smaller the difference between the two numbers, the greater the product of the two numbers

If ABC is three numbers that are not zero: a △ 3 / 5 = B △ 1 / 4 = C × 3 / 4, please arrange ABC in the order from big to small ()
One fifth less than 30 tons is () tons, and 6 meters is 15% less than (a fraction of) meters
If ABC is three numbers that are not zero: a △ 3 / 5 = B △ 1 / 4 = C × 3 / 4, please arrange ABC in the order from big to small ()
Five out of seven kilogram soybeans can extract oil, five out of 28 kilogram soybeans, one kilogram soybeans can extract () kilogram oil, and one kilogram oil needs () kilogram soybeans
Three out of eight boys in class 6 (1) are equal to four out of five girls. The ratio of boys to girls is (): ()
Judgment (detailed process should also be listed)
It took Xiaoming 5 minutes and Xiaohong 4 minutes to take the same road. The speed of Xiaoming was 20% slower than that of Xiaohong

If ABC is three non-zero numbers: a △ 3 / 5 = B △ 1 / 4 = C × 3 / 4, please arrange ABC in the order from big to small (b > a > C (positive number); C > a > b (negative number)) 5 / 3A = 4B = 4 / 3CA = 12 / 5b, a = 9 / 20c, 5 / 1 less than 30 tons is (24) tons, 6 meters less than (120 / 17) meters is 15% 30 × (1

A times 1.5 = B times 85 = C4% 3 (ABC) is not 0, ABC from small to large?

Let 1.5A = 0.85b = 0.75C = t, then a = 2T / 3, B = 20t / 17, C = 4T / 3
If t > 0, then a

Geometric meaning of second and third derivative?
The geometric meaning of the third derivative? Image or other?

There are three reasons
The most term is "the curvature of the point";
What connects with high school is "the intensity of the change of tangent slope when the point moves on the curve";
The most popular saying is "how fast the curve changes"
The essence of the three is exactly the same

Geometric meaning of second derivative

The significance is as follows: (1) the rate of change of slope of oblique line (2) the concavity and convexity of function

Is there any algebraic or geometric relationship between the second derivative of the original function and the original function?
It's mainly about the algebraic relationship. If you know a first-order derivative, you can get the second-order derivative, and then use the second-order algebraic relationship to get the analytic expression of the original function,

If you know a function, you can get the first derivative and the second derivative
Knowing the second derivative, the first derivative of the original function can be obtained by integral (the difference is a constant)
The original function can be obtained by solving the integral again (the difference is a function of degree one)
For example: y = x ^ 2 can get: y '' = 2
But y '' = 2, integral: y '= 2x + A, and then integral: y' '= x ^ 2 + ax + B

Geometric meaning of derivative?
The content of geometric meaning

Slope of tangent

How to judge that a function is a compound function when seeking the derivative of a function?

Whether it is a compound function is relative. Compound function refers to the function value of one function as the independent variable of another function. Generally speaking, compound function is based on basic function. In high school, basic function is considered as follows: first-order function (including positive proportion function), second-order function, inverse proportion function, y = x ^