Why can't we learn definite integral? What's the practical significance of finding the original function

Why can't we learn definite integral? What's the practical significance of finding the original function

The meaning of indefinite integral is to calculate the original function;
The meaning of the original function is Newton Leibniz formula
The meaning of Newton Leibniz formula is to calculate definite integral
The practical meaning of definite integral need not be explained

The relation and difference between primitive function and indefinite integral?
RT...

If f (x) is a primitive function of F (x) in interval I, then f (x) + C is the indefinite integral of F (x). The indefinite integral can express any primitive function of F (x)

To solve the quadratic equation of one variable n & # 178; - 3n-4026 = 0

n²-3n-4026=0
n=[3±√(9+16104)]/2
=(3±√16113)/2
If you don't understand, I wish you a happy study!

How many seconds can cheetah run 100 meters?

I checked the encyclopedia "cheetah from the start to the maximum speed only takes 4 seconds"
Then let's make a calculation. According to the maximum speed of 110 kilometers per hour, it's approximately 30.6 meters per second
So how far can we go in this four second acceleration time, (0 + 30.6) * 4 / 2, 61 meters
About 40 meters left, about a little more than a second
All in all, it takes a little more than five seconds
The above is only an estimate, because the condition of cheetah's acceleration of 4 seconds is not accurate. Cheetah and Cheetah are different, just like bolt and I are different

There is only one ---, and the formula containing the unknowns is ---. The degree of the unknowns is ---. Such an equation is called one variable linear equation

Unknowns, equality, 1

The average distance between the moon and the earth is about 384400 km. How many hours does it take for an aircraft to fly 1000 km per hour from the earth to the moon
I need it badly! I will die if I don't do it well the day after tomorrow~

If it's a straight line, it'll take 384.4 hours
Divide 384400 km by 1000 km
But if you want to follow the track, you need to find out the distance and divide it by 1000 kilometers
But as far as I know, airplanes don't seem to be able to fly out of the atmosphere, do they?

How to calculate 4x square minus 4x minus 15 equals 0

4X square - 4x-15 = 0
4 (x-0.5) square-16 = 0
That is, (x-0.5) square = 4
So x-0.5 = 2, so x = 2.5, the calculation is finished
Hope to help you, if you are satisfied, please accept, O (∩)_ Thank you~~

Is the size and material of the contact surface related to the sliding friction
There's only one that matters. Which one

The sliding friction is only related to the vertical force and the sliding friction coefficient of the sliding surface. The sliding friction coefficient is related to the material, but has nothing to do with the contact area. That is to say, the change of the contact area will not change the friction force, but the change of the material will change it

2x-6 = 10 equals

2X-6=10
2x=10+6
2x=16
x=8

The distance between a and B is 1980 km. The freight car departs 80 km / h from a and the car departs 85 km / h from B. how many hours do the two cars meet at the same time
The distance between a and B is 1980 km. The freight car departs 80 km / h from a and the car departs 85 km / h from B. how many hours do the two cars meet at the same time?

Let's meet in X hours
80x+85x=1980
x=12