Mobile calculator, what is the meaning of E in the calculation results?

Mobile calculator, what is the meaning of E in the calculation results?

What's the power of ten
What does e stand for in the calculator result (1.845e + 19)?
e = 2.718281828459
What is the meaning of the calculator?
You must be a scientific calculator. Many keys have two functions. Use this key to switch. 2nd - second, f (function) - function. 2ndf - second function
In the interval [1 / 2,2], if f (x) = x ^ 2 + PX + Q and G (x) = x + (1 / x) + 1 have the same minimum value at the same point, then f (x) in [1 / 2,2]
What is the maximum value on the?
The minimum value of G (x) = x + 1 / x + 1 ≥ 2 √ (x * 1 / x) + 1 = 3 in [1 / 2,2] is g (1) = 3, so f (1) = 3, that is, P + q = 2, and because the minimum value of F (x) in [1 / 2,2] is obtained at x = 1, then x = 1 must be the symmetry axis of F (x), otherwise, according to the image, the minimum value must be obtained at the endpoint (1 / 2 or 2), so - P / 2 = 1, P = - 2, q = 4f (x) =
f '(x)= 2x+p , g'(x)=1- 1/x²
f '(x)= g'(x) =0
2x+p = 1- 1/x² = 0
x=1, p=-2
Therefore, when x = 1, f (x) and G (x) get the minimum
f(1)=p+q+1 , g(1)= 3
f(1)=g(1)
So, P + q = 2, that is, q = 4
f(x)= x² -2x + 4
= (x-1)²+3
The maximum value of F (x) on [1 / 2,2] is f (2) = 4
Given that the vectors AB are not collinear and the real number XY satisfies the vector equation 3xa + (10-y) B = 2xb (4Y + 4) a, then x =? Y =?
3xa + (10-y) B = 2xb "+" (4Y + 4) a
[3x-4y-4]a＋[10-y-2x]b＝0.
a. B is not collinear: 3x-4y-4 = 0.10-y-2x = 0
(if it's "-", please make a calculation by yourself.)
Calculator M+
M +, M -, Mr, MC are the storage keys of the calculator. M + key: when the calculation result or a certain value has appeared on the screen, press m + key, the calculator will save the number on the screen to the memory. At this time, the calculation is interrupted, and you can start to press the new number for new operation again. If you press m + key again, the current number on the screen will be
It doesn't make sense! You can record a certain value
Add the sum of the values to the current MR register to give the value
M+
: add the current value to the M register, Mr can give the sum
M +, M -, Mr, MC are the storage keys of the calculator
M + key: when the calculation result or a certain value has appeared on the screen, press the M + key, the calculator will save the number on the screen to the memory. At this time, the calculation is interrupted, and you can start to press the new number for new operation again. If you press the m + key again, you will add the number in front of the screen and the number in the memory just now, and then save the calculation result in the memory.
For example, press these keys: 45 × 3 = m + 12 × 3 = M+
When "45 × 3 =" is pressed, the screen... Expands
M +, M -, Mr, MC are the storage keys of the calculator
M + key: when the calculation result or a certain value has appeared on the screen, press the M + key, the calculator will save the number on the screen to the memory. At this time, the calculation is interrupted, and you can start to press the new number for new operation again. If you press the m + key again, you will add the number in front of the screen and the number in the memory just now, and then save the calculation result in the memory.
For example, press these keys: 45 × 3 = m + 12 × 3 = M+
When "45 × 3 =" is pressed, 135 will appear on the screen. When "m +" is pressed, 135 will be stored in the memory. You can continue to press other data to start a new operation. When "12 × 3 =" is pressed, 36 will appear on the screen. When "m +" is pressed again, the calculator will perform internal operation, add 36 and 135, and save the final result 171 in the memory.
M-key: m - is the opposite of M +, which is to subtract the number on the current screen from the data in the memory, and then store the result.
Mr key: when there is data in the memory, press Mr key to display the data in the memory on the screen
MC key: clear the data stored in the memory and return the number to zero.
These but I according to own experience summary, a word a word knock up, not copy paste, ha ha, hope to help you! Put it away
M +, M -, Mr, MC are the storage keys of the calculator
M + key: when the calculation result or a certain value has appeared on the screen, press the M + key, the calculator will save the number on the screen to the memory. At this time, the calculation is interrupted, and you can start to press the new number for new operation again. If you press the m + key again, you will add the number in front of the screen and the number in the memory just now, and then save the calculation result in the memory.
For example, press these keys: 45 × 3 = m + 12 × 3 = M+
When "45 × 3 =" is pressed, the screen... Expands
M +, M -, Mr, MC are the storage keys of the calculator
M + key: when the calculation result or a certain value has appeared on the screen, press the M + key, the calculator will save the number on the screen to the memory. At this time, the calculation is interrupted, and you can start to press the new number for new operation again. If you press the m + key again, you will add the number in front of the screen and the number in the memory just now, and then save the calculation result in the memory.
For example, press these keys: 45 × 3 = m + 12 × 3 = M+
When "45 × 3 =" is pressed, 135 will appear on the screen. When "m +" is pressed, 135 will be stored in the memory. You can continue to press other data to start a new operation. When "12 × 3 =" is pressed, 36 will appear on the screen. When "m +" is pressed again, the calculator will perform internal operation, add 36 and 135, and save the final result 171 in the memory.
M-key: m - is the opposite of M +, which is to subtract the number on the current screen from the data in the memory, and then store the result.
Mr key: when there is data in the memory, press Mr key to display the data in the memory on the screen
MC key: clear the data stored in the memory and return the number to zero.
Experience summary
1302_ Six hundred and forty-five
The problem of first order equation of one variable
Hongyuan mall originally planned to sell Party A and Party B at 1500 yuan. By adjusting the price, party a raised the price by 20% and Party B reduced the price by 30%. Actually, it sold at 1600 yuan. How much is the actual price of Party A's goods
If the original price of a is x, then B is (1500-x)
1.2X+0.7(1500-X)=1600
X =1100
Then B is 400
How much is the actual price of commodity a?
1100 times 1.2 = 1320
1100 yuan for a and 400 yuan for B
How to factorize 4x * x + 4xy-3y * y + 2x + 11y-6
4x^2+4xy-3y^2+2x+11y-6
=(2x-y)(2x+3y)+2x+11y-6
=(2x-y)(2x+3y)+3(2x+3y)-4x+2y-6
=(2x+3y)(2x-y+3)-2(2x-y+3)
=(2x-y+3)(2x+3y-2)
Steps:
4x^2+4xy-3y^2+11y-6
=(2x+y)^2-4y^2+11y-6
=(2x+y)^2-(4y^2-11y+6)
=(2x+y)^2-(y-3)(4y+1)-9
Where ^ 2 is the second power.
p. Q is the maximum and minimum of the function f (x) = - 2x + 3 [- 2,2]. Find the maximum and minimum of the function g (x) = 2x ^ 2-px + Q [- 2,2]
18 and 7
Given that the vectors a and B are not parallel, find the real number x, y satisfying the vector equation 3xa + (10-y) B = (4Y + 7) a + 2xa
A and B in the equation are vectors
3xa+(10-y)b=(4y+7)a+2xa
So after moving the items and merging the similar items, we get: (x-4y-7) a + (10-y) B = 0
Because a and B are not parallel, x-4y-7 = 0 and 10-y = 0
So x = 47, y = 10