Given that x = 1 / 3 of the root sign, find the root sign of xsquare-xsquare-2x + 1 minus 1-2x + xsquare of xsquare-1square

Given that x = 1 / 3 of the root sign, find the root sign of xsquare-xsquare-2x + 1 minus 1-2x + xsquare of xsquare-1square

x=√3/3

Given that x = root 5 minus 1 / 4, then the square of x-2x-2 =?

X can be reduced to x = radical 5 + 1, then the square of x-2x-2 = (x-1) square-3, and the result is 2

It is known that the domain of F (x) is D, and f (x) satisfies the following conditions: 1. F (x) is a monotone function on D. 2. If there exists an interval [a, b] belonging to D, such that the domain of F (x) on [a, b] is [a, b], then f (x) is called a closed function
(1) Find the interval of closed function f (x) = - X3 meeting condition 2 [a, b]
(2) Judge whether the function f (x) = 3-4x + 1-x is a closed function. If so, explain the reason and find the interval that meets condition 2
(3) If f (x) = K + (x + 2) 1 / 2 [K + radical (x + 2)] is a closed function, try to find the value range of real number K

(1)[a,b]=[-1,1]
(2) No
（3）
Brother, it will be better if you make it clear

Find ten approximations from the newspaper
When do you think approximate numbers are needed in life?

For example: 122 = 120 (do you understand it?) (if not, there is this answer) 12 = 10

How much is the original price of a commodity, which is first reduced by 10%, then increased by 10% and sold for 99 yuan?

99 (1 + 10%) / (1-10%) = 99 / 1.1 / 0.9 = 90 / 0.9 = 100 yuan; answer: the original price of this product is 100 yuan

Product (1-2 to the second power) (1-3 to the second power) (one of the powers of 1-10)

(1- 1/2^2 )(1- 1/3^2 )…… （1- 1/10^2）
=(1/2)*(3/2)*(2/3)*(4/3)…… *(9 / 10) * (11 / 10) middle term offset
=(1/2)*(11/10)
=11/20

Given A-B = 4, the square of AB + m - 6m + 13 = 0, find the a power of M + B power of M =?

AB + M & sup2; - 6m + 13 = 0m & sup2; - 6m + 9 + 4 + AB = 0 (M-3) & sup2; + AB + 4 = 0 ∵ A-B = 4 ∵ a = 4 + B is substituted by (M-3) & sup2; + AB + 4 = 0 to get (M-3) & sup2; + B & sup2; + 4B + 4 = 0 (M-3) & sup2; + (B + 2) & sup2; = 0m = 3, B = - 2, the power of a = 2m + the power of B of M = the negative quadratic power of 3 + 3 &

A product is sold at a 20% discount, "20% discount" means 80% of the original price. A dictionary priced at 9 yuan still earns 20% when it is sold at a 20% discount. What's the purchase price of this dictionary
() yuan

Let the purchase price be X
Profit margin = (selling price purchase price) / purchase price
20%=（9*0.8-x）/x
X = 6 yuan
It's a waste of time. Please take it~

What is the square root of 16______ In scientific notation: - 0.00168 ≈______ (keep two significant numbers)

(1) ∵ 16 = 4, the square root of 4 is ± 2, the square root of 16 is ± 2; (2) expressed by scientific notation: - 0.00168 = - 1.68 × 10-3, retained two significant numbers can be expressed as: - 1.7 × 10-3

1. Given a + B = - 2, ab = - 3, find the value of algebraic formula 2 (4a-3b-2ab) - 3 (2a-8 / 3B + AB)
2. Please explain that the value of polynomial 3x ^ 2-4x + 6x ^ 2 + 2-9x ^ 2 + 4x-5 has nothing to do with the value of X
3. Write two similar terms of - 4x ^ 2Y and calculate the sum of these three similar terms

1.2(4a-3b-2ab）-3（2a-8/3b+ab）=2a+2b-7ab=2(a+b)-7ab=-4+21=17
2.3x ^ 2-4x + 6x ^ 2 + 2-9x ^ 2 + 4x-5 = (3 + 6-9) x ^ 2 + (- 4 + 4) x + (2-5) = - 3, which has nothing to do with the value of X
3. There are many answers to this. Write them casually
-Two similar terms of 4x ^ 2Y: 2x ^ 2Y, 3x ^ 2Y, their sum is x ^ 2Y