Inverse trigonometric function table Inverse trigonometric function table It's the sine, cosine, tangent value corresponding to each angle value It's better to show how to find inverse trigonometric functions by hand

Inverse trigonometric function table Inverse trigonometric function table It's the sine, cosine, tangent value corresponding to each angle value It's better to show how to find inverse trigonometric functions by hand

arcsin0 = 0,
arcsin (1/2) = π/6,
arcsin(√2/2) = π/4,
arcsin(√3/2) = π/3,
arcsin 1 = π/2
atccos1 = 0,
arccos (√3/2) = π/6,
arccos (√2/2) = π/4,
arccos (1/2) = π/3,
arccos 0 = π/2
arctan0 = 0,
arctan (√3/3) = π/6,
arctan (1) = π/4,
arctan (√3) = π/3,
arctan 0 = π/2

Inverse trigonometric function table

You can use the calculator that comes with windows
Start - program - Accessories - Calculator - check - Scientific - Inv - input function value - point corresponding trigonometric function symbol

Inverse trigonometric function: arctg (- 238.06162) / 213.8381 =?

0.41975 ° 0.007326 rad

Inverse trigonometric function equation arctg (x) + arctg (3x) = 90 ° give a rough algorithm on the line

If a = arctg (x), then 90 ° - a = arctg (3x)
Then x = Tan (a), 3x = Tan (90 ° - a) = cot (a)
So 3x = 1
X = √ 3 △ 3 (negative value is not allowed)

Arctg (0.1 / 0.75) = 7.576 degrees, then - arctg (0.1 / 0.75) =?

If arctg (0.1 / 0.75) = 7.576 degrees, - arctg (0.1 / 0.75) = - 7.576 degrees or (180-7.576) = 172.424 degrees

Proof of determinant of linear algebra prove 1+a1 1 1 ...1 1 1+a2 1 ...1 1 1 1+a3 ...1 . 1 1 1 ...1+an =A1A2... An (1 + 1 / AI)

Classic old topic
I'll write some steps and I'll see them
(1) Starting from the second line, each row subtracts the first line
1+a1 1 1 ...1
-a1 a2 0 ...0
-a1 0 a3 ...0
.
-a1 0 0 ...an
(2) The second line is divided by A2, the third line is divided by A3... And the nth line is divided by an
1+a1 1 1 ...1
-a1/a2 1 0 ...0
-a1/a3 0 1 ...0
.
-a1/an 0 0 ...1
*(a2a3...an)
(3) Subtract the following lines from the first line
M 0 0 ...0
-a1/a2 1 0 ...0
-a1/a3 0 1 ...0
.
-a1/an 0 0 ...1
*(a2a3...an)
The M position is: (1 + A1) + A1 / A2 + A1 / A3 +... + A1 / an
(4) Original formula = m * (a2a3... An)
=A1A2... An (1 + 1 / AI)

The proof of linear algebra uses the definition of determinant to prove that if there are more than n ^ 2-N elements of an n-order determinant as 0, then the determinant is 0

According to the drawer principle, at least one line of elements is 0
Determinant definition is the accumulation of all elements of different rows and columns
If a row is all 0, then each of the above items is 0, so the determinant is 0
It's a property, but it's only a step further than the definition. You just don't use the property directly

How to prove the property 6 of determinant in Tongji version of linear algebra

Divide the determinant of 5 into two determinants
One of them is equal to the original determinant, and the other is proportional to 0

Determinant property 5 how to prove, Tongji version of linear algebra

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In engineering mathematics linear algebra Tongji fifth edition P10 property 2 two rows (columns) of commutative determinant, determinant change sign. The proof process is a little incomprehensible   Set determinant     It is obtained by the determinant d = det (AIJ) replacing the two rows I and j, that is, if   When k ≠ I, J, BKP = AKP; when k = I, J, BiP = AJP, BJP = AIP             D1=  ∑(-1)tb1p1… bipi… bjpj… bnpn               =  ∑(-1)taip1… ajpi… aipj… anpn               =  ∑(-1)ta1p1… aipj… ajpi… anpn   Among them, 1 i… j… N is natural permutation, t is permutation P1 pi… P J ... Let the permutation P1 pj… pi… The reverse order number of PN is   Then (- 1) t = - (- 1) T1        Dj=  -∑(-1)t1a1p1… aipj… ajpi… anpn=   -D   The above is the complete proof process on the book   The other parts are very clear, of which I don't understand the most   Does it mean that in the latter step, DJ = - D = - 1   t1a1p1… aipj… ajpi… Anpn? However, D is the newline (column)   The previous determinant is not supposed to be   D=∑(-1)ta1p1… aipi… ajpj… Anpn?   Unless I have a problem with my thinking. Then if I have a problem with my thinking   How is the equation of the last step derived   What about it? I don't have a good math foundation. I want to do well   Understand the knowledge in the textbook  

You are the same as I thought before. Now I have understood. To understand this step, you have to be very clear about the definition of the expression of determinant. Determinant is the algebraic sum of n! Terms. Each term is the product of N numbers in different columns in different rows, plus the t power of sign (- 1). The key is how to get t, which is how to get every