Why SiNx / 2 + √ 3cosx / 2 = 2Sin (x / 2 + π / 3)?

Why SiNx / 2 + √ 3cosx / 2 = 2Sin (x / 2 + π / 3)?

sin(x/2)+√3cos(x/2)
=2*[1/2*sin(x/2)+√3/2*cos(x/2)]
=2[sin(x/2)cosπ/3+cos(x/2)sinπ/3]
=2sin(x/2+π/3)

Verification: Geng No. 3cosx SiNx = 2Sin (PAI / 3-x)

Certificate:
Left = √ 3cosx SiNx
=2（√3/2cosx-1/2 sinx）
=2（sinπ/3 cosx-cosπ/3 sinx）
=2Sin (π / 3-x) = right
The proof is complete
I hope I can help you. Happy study

How many decimeters, meters and kilometers is 500000 cm equal to,

50000 decimeters = 5000 meters = 5 kilometers

123456789 these nine numbers, do not change the order, with the addition and subtraction sign connected, so that the result is equal to 100

Hello!
123-4-5-6-7+8-9=100
I hope my answer will help you

Practical problems: 5 / 6 minus a fraction, 4 / 9 plus the same fraction, their results are equal, what is the fraction?

Let this fraction be x 5 / 6-x = 4 / 9 + x 5 / 6-4 / 9 = x + x 30 16__ - __ =2X 36 36 X=7/36

How many tons of water is one cubic meter of water

A liter of water is 1kg, a cubic meter of water is 1000kg, is a ton of water

Elementary equation of first degree with two variables
A logistics company has 31 tons of goods. It plans to rent a car of type A and B car of type B at the same time. The goods are transported at one time, and each car is full of goods
1: : how many tons can a type a car and a type B car be loaded with goods at one time?
2: Please help the logistics company design a car rental scheme
3: If the rent of a car is 100 yuan and that of B car is 120 yuan, please choose the most economical plan and find out the least rental fee

It is known that: two A-type cars and one B-type car can transport 10 tons of goods at a time; one A-type car and two B-type cars can transport 11 tons of goods at a time. A logistics company has 31 tons of goods. It plans to rent A-type car and B-type car at the same time, and each car is full of goods
(1) How many tons of goods can be transported by one A-type vehicle and one B-type vehicle when they are fully loaded?
(2) Please help the logistics company design a car rental scheme
(3) If the rent of a car is 100 yuan per car and that of B car is 120 yuan per car, please choose the most economical car rental scheme and find out the minimum rental fee
(1) Set up a series of equations, let a transport x tons per vehicle, B transport y tons per vehicle
2X+Y=10
X+2Y=11
The solution is x = 3, y = 4
Therefore, a type a vehicle with full load carries 3 tons of goods at a time, and a type B vehicle with full load carries 4 tons of goods at a time
(2) A car a, B car B is known by a small problem that a is 3 tons at a time, B is 4 tons at a time, a total of 31 tons are transported at one time
Lie equation: 3A + 4B = 31
Solvable a = 1, B = 7; a = 5, B = 4; a = 9, B = 1
(3) Which of the three car rental schemes is the most economical
Three equations: 100A + 120b = y
When a = 1, B = 7, the solution is y = 940
When a = 5, B = 4, the solution is y = 980
When a = 9, B = 1, the solution is y = 920
So choose the third scheme, 9 a car and 1 B car, the minimum rental fee is 920 yuan

39×37-13×11
Simple calculation method

39×37-13×11
=13*3*37-13*11
=13*（3*37-11）
=13*（111-11）
=13*100
=1300

Mathematical calculation method of Excel
There is a multiplier a, three multiplicees B, C, D, and the quotient is e. it is required to insert a formula in Excel. When a is greater than or equal to 30, the result of e equals AB; when a is greater than or equal to 30 and less than 38, the result of e equals 30b + (A-30) * C; when a is greater than or equal to 38, the result of e equals 30b + 37C + (a-37) * D
The result of E can be calculated automatically in the answer column

=if(A1

It is known that the square of a minus the square of B = one fifth, the square of a plus the square of B = 2 and one-quarter, and the power of (AB) is obtained
Wrong. That's A-B = one fifth

∵a-b=1/5
∴(a-b)∧2=1/25
∴a∧2+b∧2-2ab=1/25
∵ a ∧ 2 + B ∧ 2 = 2 and 1 / 25 = 51 / 25
∴2ab=2
∴ab=1
∴（ab）∧2005=1