Given SiNx = 2cosx, find three function values of angle X

Given SiNx = 2cosx, find three function values of angle X

sinx=2cosx
sinx/cosx=2
tanx=2
sinx=2/√5=2√5/5
cosx=1/√5=√5/5
tanx=2
sinx=+-2/5^1/2
cosx=+-5^1/2
sinx/cosx=2=tanx
x=arctan2
Look up the table or calculate x = 63.43 ° with calculator
be
sinx=0.89
cosx=0.447
tanx=2
ctanx=0.5
On the calculation of factorization
1.22^2X9-1.33^2X4=?
Note: 1.22 ^ 2 means the square of 1.22
Original formula = 1.22 ^ 2 × 3 ^ 2-1.33 ^ 2 × 2 ^ 2 = (1.22 × 3) ^ 2 - (1.33 × 2) ^ 2 = (1.22 × 3-1.33 × 2) × (1.22 × 3-1.33 × 2)
I can only do this step, I don't know, right
sinx+sin(x+2/3π)+sin(x-2/3π)
The original formula is 1 / 2 - 1 / 2cos2x + 1 / 2 - 1 / 2cos (2x + 4 π / 3) + 1 / 2 - 1 / 2cos (2X-4 π / 3) = 3 / 2 - 1 / 2cos2x - 1 / 2cos2xcos (4 π / 3) + 1 / 2sin2xsin (4 π / 3) - 1 / 2cos2xcos4 π / 3 - 1 / 2sin2xsin4 π / 3 = 3 / 2 - 1 / 2cos2x + 1 / 4cos2x - √ 3 / 4sin2x + 1 / 4cos2x + √ 3 / 4sin2x = 3 / 2
Several calculation problems of factorization
(1) The square of (x + y) - 1
(2) The fourth power of a times the second power of X - the fourth power of a times the second power of Y
(3) The square of 3x + 6xy + the square of 3Y
(4) Square of (X-Y) + 4xy
(5) The square of 4a-3b times (4a-3b)
(1) The square of (x + y) - 1
=(x+y+1)(x+y-1)
(2) The fourth power of a times the second power of X - the fourth power of a times the second power of Y
=a^4(x^2-y^2)
=a^4(x+y)(x-y)
(3) The square of 3x + 6xy + the square of 3Y
=3(x+y)^2
(4) Square of (X-Y) + 4xy
=x^2-2xy+y^2+4xy
=x^2+2xy+y^2
=(x+y)^2
(5) The square of 4a-3b times (4a-3b)
=4a^2-12ab+9b^2
=(2a-3b)^2
Square of (x + y) - 1 = (x + y + 1) (x + Y-1)
The fourth power of a times the second power of X - the fourth power of a times the second power of y = a ^ 4 * (x + y) (X-Y)
The square of 3x + 6xy + 3Y = 3 (x + y) ^ 2
Square of (X-Y) + 4xy = (x + y) ^ 2
Square of 4a-3b times (4a-3b) = (2a-3b) ^ 2
(1) Square of (x + y) - 1 (difference of squares)
=(x+y+1)(x+y-1)
(2) The fourth power of a times the second power of X - the fourth power of a times the second power of Y
=A to the fourth power (x to the second power - y to the second power) (difference of squares)
=The fourth power of a (x + y) (X-Y)
(3) The square of 3x + 6xy + the square of 3Y
=3 (square of X + 2XY + square of Y) (complete square formula)
=The square of 3 (x + y)
(4) (x) expand
(1) Square of (x + y) - 1 (difference of squares)
=(x+y+1)(x+y-1)
(2) The fourth power of a times the second power of X - the fourth power of a times the second power of Y
=A to the fourth power (x to the second power - y to the second power) (difference of squares)
=The fourth power of a (x + y) (X-Y)
(3) The square of 3x + 6xy + the square of 3Y
=3 (square of X + 2XY + square of Y) (complete square formula)
=The square of 3 (x + y)
(4) Square of (X-Y) + 4xy
=The square of X - 2XY + the square of Y + 4xy
=Square of X + 2XY + square of Y
=The square of (x + y)
(5) The square of 4a-3b times (4a-3b)
=The square of 4A - the square of 12ab + 9b
=The square of (2a-3b) is folded
(1) The square of (x + y) - 1
=(x+y+1)(x+y-1)
(2) The fourth power of a times the second power of X - the fourth power of a times the second power of Y
=a^4(x+y)(x-y)
(3) The square of 3x + 6xy + the square of 3Y
=3(x²+2xy+y²）
=3(x+y)²
(4) Square of (X-Y) + 4xy
=X & # 178; - 2XY + Y & # 178; +... Expansion
(1) The square of (x + y) - 1
=(x+y+1)(x+y-1)
(2) The fourth power of a times the second power of X - the fourth power of a times the second power of Y
=a^4(x+y)(x-y)
(3) The square of 3x + 6xy + the square of 3Y
=3(x²+2xy+y²）
=3(x+y)²
(4) Square of (X-Y) + 4xy
=x²-2xy+y²+4xy
=x²+2xy+y²
=(x+y)²
(5) The square of 4a-3b times (4a-3b)
=4a²-12ab+9b²
=(2a + 3b) &
How to transform y = SiNx into y = sin (x / 2 + π / 3)
First, the abscissa is expanded twice, and then the image is shifted to the left by π / 3 units. You can also shift the image to the left by 2 π / 3 units, and then the abscissa of the image is expanded twice
On the calculation of factorization,
2002^2—2001^2+2000^2—1999^2+1998^2—…… +2^2—1^2
^2 is the square of the previous number
It's better to have a process, otherwise analysis can be done
The original formula of square difference = (2002-2001) (2002 + 2001) + (2000-1999) (2000 + 1999) + +(2-1) (2 + 1) the first bracket of each item is equal to 1, so = 2002 + 2001 + 2000 + 1999 + +2+1=(2002+1)+(2001+2)+…… +(1002+1001)=2003×1001=2005003...
2002^2—2001^2+2000^2—1999^2+1998^2—…… +2^2—1^2
=(2002-2001)(2002+2001)+(2000-1999)(2000-1999)+(1998-1997)(1998-1997)
+.....+(2-1)(2+1)
=2002+20001+2000+1999+1998+....+2+1
=(1+2002)*2002/2
=2003*1001
=2005003
Find SiNx = (1 / 3), 2 π < x < 3 π, then sin (x / 2) + cos (x / 2)
2π＜x＜3π π＜x/2＜3π/3 sin（x\2） ＋ cos（x\2)
∵2π＜x＜3π
∴ π＜x/2＜3π/3
∴ sin（x\2） ＋ cos（x\2)
In the three integers x2 + 2XY, Y2 + 2XY, X2, please choose any two to add (or subtract) so that the resulting integers can be factorized and factorized
Method 1: (x2 + 2XY) + x2 = 2x2 + 2XY = 2x (x + y); method 2: (Y2 + 2XY) + x2 = (x + y) 2; method 3: (x2 + 2XY) - (Y2 + 2XY) = x2-y2 = (x + y) (X-Y); method 4: (Y2 + 2XY) - (x2 + 2XY) = y2-x2 = (y + x) (Y-X)
What does PI refer to!
Pi = proforma invoice, valuation invoice, trial invoice, reference note
effect:
1. Let the customers know what they buy, how much the quantity is, how much the unit price is, and how much the total value is;
2. Documents used by customers to apply for L / C or other payment methods
The function of proforma invoice (PI) is equivalent to quotation. Can production be arranged by making a good quotation? Isn't it too easy to do trade?
Only after the two parties sign the proforma invoice, it means that the contract will come into effect! – but only when the contract comes into effect, it does not necessarily need to arrange production - usually production can be arranged only after LC or advance payment is received!
Proforma invoice can't arrange production after it is finished. Another function of proforma invoice is to use it as a contract. It needs to be stamped by both parties before it can take effect! My British customer likes to use Pi as a contract every time, and he will pay a deposit when he receives PI!
Proforma invoice can also be used for other occasions that need settlement
(1) For prepayment, i.e. cash payment before loading
(2) In the way of consignment, the exported goods are put in the hands of agents instead of definite sales contract. For agents, proforma invoice can be used as a guide to quote prices to potential buyers
(3) In case of bidding, proforma invoice enables the buyer to sign sales contract with many competing suppliers at reasonable price and sales terms
In foreign investment, PI is proforma invoice. In fact, the customer said to remit money to you. Generally, the PI will write the bank information of your company, that is, the export company, on it, including the account number, account name, name and address of the opening bank, as well as swift No. You can just give him all the bank information.
PI has other meanings
PI
ABR
1. = private investigator
... unfold
In foreign investment, PI is proforma invoice. In fact, the customer said to remit money to you. Generally, the PI will write the bank information of your company, that is, the export company, on it, including the account number, account name, name and address of the opening bank, as well as swift No. You can just give him all the bank information.
PI has other meanings
PI
ABR
1. = private investigator
2. = productivity index
3. = Plastics Institute
Proforma invoice
Factorization of practical problems
Second day of junior high school
1. Two students decompose the same quadratic trinomial into one factor, one student decomposes it into (x-1) (X-9) because he misread the coefficient of the first term, and the other student decomposes it into (X-2) (x-4) because he misread the coefficient of the first term