Trigonometric function value table 0.1-1 degree function value TGA = 0.004, find a? TGB = 0.008, B?

Trigonometric function value table 0.1-1 degree function value TGA = 0.004, find a? TGB = 0.008, B?

The function value of such a small angle can be approximately equal to the radian of its angle!
Because,
Proof of small angle
sin 0.004=0.004,
con0.004=1,
TGA = 0.004, a = 0.004 (radian) = 0.004 * 180 / π = 0.229183118 degrees;
TGB = 0.008, B = 0.008 (radian) = 0.008 * 180 / π = 0.458366236 degrees
What is the formula for finding the true subset and the non true subset of a set
Just use the number 8 to make up five numbers and fill in the box below to make the formula true______ ﹢______ ﹢______ ﹢______ ﹢______ =1000．
According to the stem analysis can be: 888 + 88 + 8 + 8 + 8 = 1000, so the answer is: 888; 88; 8; 8; 8
Trigonometric function problem (2) cos45 degree - sin30 degree / cos60 degree + half tan45 degree
Cos 45 degrees - Sin 30 degrees / cos 60 degrees + Half Tan 45 degrees
=Half root 2-half / half + Half * 1
=Root of half sign 2-1 + Half
=Two thirds (radical 2-1)
Radical 2 / 2 - 1 + 1 / 2 = (radical 2 - 1) / 2
cos45°-sin30°/cos60° +1/2tan45°
=√2/2 -(1/2)/(1/2)+ 1/2*1
=√2/2-1+1/2
=√2/2-1/2
(cos45°－sin30)/[cos60°＋(1/2)tan45°]
=[(√2/2)－(1/2)]/[(1/2)＋(1/2)]
=(√2－1)/2
Formula expression of the number of subsets and the number of proper subsets
If there are n elements in a finite set a, then there are 2 ^ n subsets and (2 ^ n) - 1 proper subsets of A
As shown in the figure, all denominators are four digits. Please fill in a number in each square to make the equation true
19990 + 11998 = 11665
In the triangle ABC, the opposite sides of the angles a, B and C are a, B, C and a = 60 degrees respectively. Find the value of b-2c / A * cos 60 degrees + C
I forgot to add brackets, which is to find the value of b-2c / A * cos (60 degrees + C)
How to find the proper subset of a set? Is there any formula?
For example: what is the number of proper subsets of the set M = {2,4,6}?
If we want to find the number of proper subsets, then the nth power of 2 is - 1, and N is the number of elements in the set
2^3-1=7
All denominators are four digits. Please fill in one digit in each square to make the equation 1 / () + 1 / 1990 = 1 / () ()
It's not 1988
1/7960+1/1990=1/1592
The number of proper subsets is required. There is a formula 2 ^ n-1, but it is wrong to use it here. The set {13579} has several proper subsets, and the answer is 31. I use this formula to find
The number is 16. What's wrong
There are five elements in {1,3,5,7,9} set, so n = 5, then the number of proper subsets is:
(2^n)-1
=(2^5)-1
=32-1
=31
You get: 2 ^ (n-1) = 2 ^ 4 = 16
Note: the formula is: 2 to the power of N - 1, first multiply and then subtract 1
Instead of: the (n-1) power of 2!
That is to use this formula, n is the number of elements, minus one is the same as the original set. So this question is like this: 2 ^ 5 equals 32, and then minus 1 equals 31