(2cos10°-sin20°)/sin70°=? Help write down the process, thank you

(2cos10°-sin20°)/sin70°=? Help write down the process, thank you

Sin20 = sin (30-10) so (2cos10 ° - sin20 °) / sin70 ° = (2cos10 ° - sin (30-10)) / sin70 ° = (2cos10 - (sin30cos10-cos30sin10)) / sin70 = (2cos10-1 / 2cos10 + radical 3 / 2sin10) / sin70 = (3 / 2sin10 + radical 3 / 2sin10) / sin70 = radical 3
If (A-2) & sup2; + B + 3 = 0, then the value of (a + b) & sup2; & ordm; & sup1; & sup1; is? (ask for the process and explain)
A new operation "￥": a ￥ B = B & sup3;, such as 3 ￥ 2 = 2 & sup3; = 8,
How much is 3 ￥ & frac12
If a & sup2; = (- 2) & sup2;, then a =?
(1) From (A-2) & sup2; + B + 3 = 0
（a-2）²=0,|b+3|=0
So a = 2, B = - 3
So (a + b) & sup2; & ordm; & sup1; & sup1; = - 1
(2) According to the meaning of the title, 3 ￥ & frac12; = (1 / 2) ^ 3 = 1 / 8
A = 2 or - 2 is known from a & sup2; = (- 2) ^ 2 = 4
（a+b）²º¹¹=-1
a-2=0
b+3=0
a+b=-1
(a+b)²º¹¹=-1
a￥b=b³
3￥½=1/8
a²=（-2）²
a=±2
It can be seen from the question that: (A-2) & sup2; = 0 | B + 3 | = 0
Then A-2 = 0, B + 3 = 0
So a = 2, B = - 3
Then {a + B} & sup2; & ordm; & sup1; & sup1; = 1
Cos θ = 1 / 2, how many degrees does θ equal =. =,
2K π + π / 3 or 2K π - π / 3
60°
2K π + π / 3K is an integer
2kπ±π/3
How many parts of a kilogram is 350 kilogram?
Who knows? Is it 350 out of 1000? And then simplify it,
It's 350 grams
In this case, 1g = 1 / 1000 kg,
So 350 g = 350 × 1 / 1000 kg = 350 / 1000 kg, and then simplify to 7 / 20
What is the angle of COS equal to 1?
The angle cos equals 1 is 0, or 2K π (k is an integer)
Zero
0 degree
2K π (k is a natural number)
0 degree, cos0 = sin90 = 1
cos(2kπ)=1 k∈Z
Of course, 0 is the simplest
2n π, where n = 0,1,2,3
2K π K belongs to Z
cos0°=1
Draw a circle arbitrarily and increase its radius by 1 / 4. What is the current area?
25/16
If the radius is increased by a quarter, then the current radius is 5 / 4 of the original, and the area formula is s = π R & # 178; let the original radius be 1, then the current radius is 5 / 4, and substitute it into the area formula, the original area is π, and the current area is 25 / 16 π. Divide the current area by the original area product to get 25 / 16
1-4sin α ^ 2 α cos ^ 2 α equals
Original formula = [1 - (2sinacosa) ^ 2]
=(1+2sinacosa)(1-2sinacosa)
=(sin^2a+cos^2a+2sinacosa)(sin^2a+cos^2a-2sinacosa)
=(sina+cosa)^2*(sina-cosa)^2
=(sin^2a-cos^2a)^2
=(cos^2a-sin^2a)^2
=(cos2a)^2
Two thirds of a ton is a fraction of four fifths of a ton, and one-half of a meter is a fraction of four fifths of a meter?
2/3÷4/5=5/6
1 / 2 △ 4 / 5 = 5 / 8 (m)
What degree is COS-1 equal to
A 180 degree computer can work it out
Cos-57.3 degrees, where 1 is a real radian
COS-1 radian = cos (- 1 * 180 / PI) = cos (- 57.296 degrees) = 0.5403023
How many parts of a meter can two seventh of a meter be regarded as?
Two seventh of a meter can be regarded as a fraction of a meter, or a fraction of a meter?
From the numbers of 1, 4, 5 and 9, choose the two largest numbers to form the largest true fraction? The smallest false fraction? In the fraction, what is the smallest number and the fraction unit? What is the fraction unit?
2 out of 7 1 out of 7