How to calculate (25 + 2.5 + 0.25) * 4.4

How to calculate (25 + 2.5 + 0.25) * 4.4

(25+2.5+0.25)*4.4
=25*4+2.5*4+0.25*4+25*0.4+2.5*0.4+0.25*0.4
=100+10+1+10+1+0.1
=122.1

Simple calculation of 4 × 0.5 × 0.25 × 2

(all letters are vectors)
Judge right and wrong and give reasons
1. If a is not equal to zero and B is not equal to zero, then a * B is not equal to zero
3. If a * B equals zero, then a equals zero, or B equals zero
2. If a * b = a * C and a is not equal to zero, then B = C

The product of any vertical vector is 0
2. The product of any vertical vector is 0
The same as above
The three problems are the same, as long as the two vectors are perpendicular, the product can be zero

The minimum positive period of function y = sin (Wu / 4-2x)

Range [- 1,1]
Period = 2 π / 2 = π
Monotonically increasing [- 3 π / 8 + K π, π / 8 + K π] K ∈ Z

The period of function 1 + sin μ x is

The minimum positive period of sine function y = asin (ω x + φ) is t = 2 π / | ω|
So the minimum positive period of 1 + sin Wu x is:
T=2π/π=2
The general cycle is 2K

Given that the minimum period of function f (x) = sin (2wx - π / 6) + 1 / 2 is π, find the value of W and the value range of function f (x) in the interval [0,2 π / 3]

According to the meaning of the title:
π=2π/(2w)
The solution is: w = 1
f(x)=sin(2x-π/2)+1/2
x∈[0,2π/2]
∴-π/6

Given the function f (x) = - 2asin (2x + π 6) + A + B, the domain of definition is [0, π 2], and the range of value is [- 5, 4]. Find the value of constant a, B

∵ 0 ≤ x ≤ π 2, ∵ π 6 ≤ 2x + π 6 ≤ 7 π 6, ∵ 12 ≤ sin (2x + π 6) ≤ 1. When a > 0, - 2asin (2x + π 6) ∈ [- 2A, a], we obtain - 2asin (2x + π 6) + A + B ∈ [B-A, 2A + b] ∵ B − a = − 52A + B = 4, the solution is a = 3, B = - 2; when a < 0, - 2asin (2x + π 6)

Let f (x) = sin (x + θ) + root 3cos (x - θ), where θ is a constant and θ∈ (0, π), if f (x) is an even function
Finding the value of theta
Big brother, big sister, help

F (x) = sin (x + θ) + radical 3cos (x + θ)
=2[sinπ/6sin(x+θ)+cosπ/6*cos(x+θ)]
=2cos(x+θ-π/6)
Is even function
θ-π/6=kπ,k∈Z
θ=π/6+kπ,k∈Z

It is known that the maximum value of the function f (x) = sin (x + π / 6) + sin (x - π / 6) + a (x belongs to R) is the value of the constant a obtained by the root sign 3 (1)
（2） To find the set of values of X for f (x) ≥ 0

f(x)=2sinxcos(π/6)+a=√3sinx+a
The maximum value is √ 3 + a when SiNx = 1
So a = 0
If f (x) > = 0, then: √ 3sinx > = 0
That is SiNx > = 0
2kπ

The relation between the periodicity and symmetry of functions
If the image of y = f (x) is symmetric with respect to the line x = A and x = B, then the period of y = f (x) is 2|a-b|
If the image of y = f (x) is symmetric with respect to line x = A and point (B, 0), then the period of y = f (x) is 4|a-b|
If the image of y = f (x) is symmetric with respect to point (a, 0) and point (B, 0), then the period of y = f (x) is 2|a-b|
Why?