Is the function f (x) = x + change sign (X & # 178;, - 1) non odd and non even? Is the function f (x) = (1-x) even under the change sign (1 + x) / (1-x)? How about speed? I just went to the cram school, but I didn't understand what the teacher said (⊙ o ⊙)

Is the function f (x) = x + change sign (X & # 178;, - 1) non odd and non even? Is the function f (x) = (1-x) even under the change sign (1 + x) / (1-x)? How about speed? I just went to the cram school, but I didn't understand what the teacher said (⊙ o ⊙)

The function f (x) = x + under the change sign (X & # 178;, - 1) is a non odd non even function
The function f (x) = (1-x) under the change sign (1 + x) / (1-x) is also a non odd and non even function, whose domain of definition is asymmetric

Let f (x) be a function with 1 as a period, and if x belongs to (- 1,0), f (x) = 2x + 1, find the value of F (7 / 2)

F (x) is a function with a period of 1
So f (x + 1) = f (x)
f（7/2）=f(5/2)=f(3/2)…… =f(-1/2)
When x belongs to (- 1,0), f (x) = 2x + 1
f(-1/2)=0
f（7/2）=f(-1/2)=0

The period of function f (x) is 3. If f (x) = x ^ 2-2x + 1 on interval [0,3], then f (x) on interval [3,6]=

F (x) = f (x + 3), so f (x) is equal to x ^ 2-2x + 1 in [3,6]

Find Lim [1 + (sin1 / x + cos1 / x-1)] ^ x (x tends to infinity)

Let t = 1 / x, t tend to 0lim [1 + (sin1 / x + cos1 / x-1)] ^ x (x tend to infinity) = LIM (Sint + cost) ^ (1 / T) = Lim [1 + (Sint + cost-1)] ^ {[1 / (Sint + cost-1)] * (Sint + cost-1) / T} = e (because when t tends to 0, LIM (Sint + cost-1) / T = LIM (cost Sint) = 1)

What is the remainder of the result of 2006 * 2007 * 2008 divided by 7?

2006*2007*2008=（2009-3）*(2009-2）*（2009-1)=(2009²-5*2009+6)(2009-1）=2009³-5*2009²+6*2009-2009²+5*2009-6
Since 2009 can be divided by 7, only the last term - 6 is considered, that is, the number can be divided by 6, so the number divided by 7 is 1

-Simple operation of 13 × 2 / 3-0.34 × 2 / 7 + (- 13) - 5 / 7 × 0.34

﹣13×2/3－0.34×2/7＋﹙﹣13﹚－5/7×0.34
＝﹙﹣13﹚×2/3＋﹙﹣13﹚－0.34×2/7－5/7×0.34
＝﹙﹣13﹚×﹙2/3＋1﹚－0.34×﹙2/7＋5/7﹚
＝﹙﹣13﹚×5/3－0.34×1
＝﹣65/3－17/50
＝﹣3301/150
It's 3301 out of 150

The general solution of the second order nonhomogeneous differential equation y ″ - 4Y ′ + 3Y = 2e2x with constant coefficients is y=______ ．

The characteristic equation of the homogeneous equation is λ 2-4, λ + 3 = 0, and its characteristic root is λ 1 = 1, λ 2 = 3. Then the general solution of the homogeneous equation is & nbsp; Y1 = c1ex + c2e3x. Because the non-homogeneous term is f (x) = E2x, and 2 is not the root of the characteristic equation, the special solution of the original equation is & nbsp; Y1 = c1ex + c2e3x; So the general solution of the original equation is & nbsp; y = Y1 + y * = c1ex + c2e3x - 2e2x, where C1 and C2 are arbitrary constants

How much water is one liter

One liter of water is equal to two Jin of water

What's 250 times 80 vertical

250×80=20000
two hundred and fifty
× 80
——————
forty
one hundred and sixty
————
twenty thousand

Given (x + 1) ^ n = A0 + A1 (x-1) + A2 (x-1) ^ 2 +... + an (x-1) ^ n, where n ≥ 2, n ∈ n *. Let BN = 2 ^ (n-3) / A2, find B2 + B3 +... + BN

(Baidu knows that it doesn't support mathematical formulas, so it can only send you a link.)
We can get: a_ 2=C_ (n,2)*2^(n-2)=n(n-1)*2^(n-3)
So B_ n=1/n(n-1)
So B_ 2+b_ 3+...+b_ n=1/2+1/6+1/12+...+1/n(n-1)=(1-1/2)+(1/2-1/3)+(1/3-1/4)+.+1/n-1/(n-1)=1-1/(n-1)