For the function f (x) = x2-2 | x |, (1) judge its parity and point out the symmetry of the image; (2) draw the image of the function and point out its monotone interval
(1) ∵ f (- x) = (- x) 2-2 | - x | = x2-2 | - x | = f (x), ∵ f (x) = x2-2 | - x | is even function, the image of ∵ function f (x) = x2-2 | - x | - is symmetric about y axis; (2) as shown in the figure, the monotone increasing interval of ∵ function f (x) = x2-2 | - x |: (- 1, 0), (1, + ∞); monotone decreasing interval: (- ∞, - 1), (0, 1)
How to say airport in English
airport
Given that 1 + 3 = 4 = 2, 1 + 3 + 5 + 7 = 4, 1 + 3 + 5 + 7 + 9 = 5, then 1 + 3 + 5 + 7 +. + (2n-1) =?
n^2
1+3+5+7+.+(2n-1)=(2n-1)+(2n-3)+...+7+5+3+1
So 1 + 3 + 5 + 7 +. + (2n-1) = 1 / 2 * [1 + 2N-1 + 3 + 2n-3 +... + 2N-1 + 1]
=1/2*[2n*n]
=n^2
Find the shortest chord length of the line passing through point (2, - 1) cut by circle X & sup2; + Y & sup2; - 6x-2y-15 = 0
x^2+y^2-6x-2y-15=0
x^2-6x+9+y^2-2y+1=25
(x-3)^2+(y-1)^2=5^2
The distance from (2, - 1) to the center (3,1) is the root sign 5
Then the shortest chord length is 2 * radical (5 ^ 2 - (radical 5) ^ 2) = 4 radical 5
What are the English words from January to December?
January July July February August March September September September September April April October October may November June
Urgent, Tuesday! We know that the greatest common factor of a and 40 is 8, and the greatest common multiple of a and 40 is 80, so what is a equal to?
The least common multiple of a and 40 is 80
A=16
Range (process) of function 1-x & # 178 / 1 + X & # 178
Let x square = t, then t > = 0, the original formula is 1-T / 1 + T, j is equal to {- (T + 1) + 2} / T + 1, next you should know how to do it
Simple calculation of 31 * 23 of 59 + 36 + 100 of 31 * 59
We need a formula
31\59*23+31*36\59+100=31*[(23+36)\59]+100=131.
How does the physical formula V ^ - = x / T = V0 + VT / 2 = VT / 2 come from
This formula has conditions for use, V ^ - = x / T, displacement x = v0t + at ^ 2 / 2 for uniform acceleration linear motion with initial velocity of 0. Take this formula into the previous formula to get V ^ - = V0 + at / 2, and VT = VO + at, because the initial velocity is 0, so VT = at, and then substitute V0 = 0 into the previous formula to get V ^ - = x / T = V0 + VT / 2 = v
Given that there is a point a (- 1, - 1,2) in the space rectangular coordinate system o-xyz, and point B is the moving point on the straight line x + y = 1 in the xoy plane, then the shortest distance between two points a and B is ()
A. 6B. 342C. 3D. 172
Let B (m, 1-m, 0) be a moving point on the line x + y = 1 in the xoy plane. According to the distance formula between two points in space, we get | ab | = (− 1 − m) 2 + [− 1 − (1 − m)] 2 + (2 − 0) 2 = 2M2 − 2m + 9, let t = 2m2-2m + 9 = 2 (M-12) 2 + 172. When m = 12, the minimum value of T is 172 | when m = 12, | AB