Function f (x) = {- x square - 2x, - 2 ≤ x ≤ 0; X, 0 < x ≤ 2, find the maximum and minimum of F (x)

Function f (x) = {- x square - 2x, - 2 ≤ x ≤ 0; X, 0 < x ≤ 2, find the maximum and minimum of F (x)

f（x）=-x^2-2x=-(x+1)^2+1,-2≤x≤0；f(x)max=1,f(x)min=0
f(x)=x,0＜x≤2,f(x)max=2,f(x)min=0
In conclusion, f (x) max = 2, f (x) min = 0

Let g (T) be the minimum value of the function f (x) = the square of X - 2x + 2 (where x belongs to [T, t + 1], t belongs to R)
In order to save time, playing is not very standard, hope understanding

When T1, G (T) = T ^ 2-2t + 2

Let f (x) = x2-2x + 2, the minimum value of X ∈ [T, t + 1] (t ∈ R) be g (T), and find the expression of G (T)

F (x) = x2-2x + 2 = (x-1) 2 + 1, so the symmetry axis of the image is a straight line x = 1, and the opening of the image is upward. ① when t + 1 < 1, i.e. T < 0, f (x) is a decreasing function on [t, t + 1], so g (T) = f (T + 1) = T2 + 1; ② when t ≤ 1 ≤ T + 1, i.e. 0 ≤ t ≤ 1, the function f (x) gets the minimum value at the vertex, i.e. g (T) = f (1) = 1; ③ when t > 1, f (x) is at [T, t + 1] In conclusion, G (T) = T2 + 1 & nbsp;, & nbsp; & nbsp; T < 01 & nbsp;, & nbsp; & nbsp; 0 ≤ t ≤ 1t2 − 2T + 2 & nbsp;, t > 1

”The meaning of bridge in the two words of "cultural bridge" and "economic bridge"

It means communication

Is the opposite number of the third power of negative a equal to the third power of a
emergency

Equal to

The distance between the two places is 120 kilometers. Party A and Party B start from place a to place B at the same time. Party A travels 15 kilometers per hour and Party B travels 15 kilometers per hour
B travels 9 kilometers per hour, and a returns immediately after arriving at B. how many hours did it take for them to meet?

120 / 15 = 8 hours
8 * 9 = 72km
120-72 = 48 km
48 / (15 + 9) = 2 hours
Total time = 8 + 2 = 10 hours

Given that the square of a + AB = - 2, the square of 2Ab + B = 4, try to find the value of 1. The square of a + 3AB + B: the square of 2.2A - the square of B

(1) The sum of the two formulas is a square + AB + 2Ab + b square = (- 2) + 4 = 2
(2) Multiply 2 by the first formula to get 2A squared + 2Ab = - 4, and then subtract the second formula 2Ab + B squared = 4 to get 2A squared minus B squared = (- 4) - 4 = - 8

A simple calculation method: 0.9 + 9.9 + 99.9 + 999.9
A simple calculation method: 0.9 + 9.9 + 99.9 + 999.9 + 0.2 + 0.4 + 0.6 + +1.8+2

0.9+9.9+99.9+999.9
=（1+10+100+1000）-0.1×4
=1111-0.4
=1110.6
0.2+0.4+0.6+…… +1.8+2
=（0.2+2）×10÷2
=22÷2
=11

There are 8 cases of apples in the store, each of which has the same weight. If you take kg out of each case, the rest is exactly equal to the weight of the original 6 cases. How many kg in each case?

Let's set the original x kg
8X-2*8=6X
8X-6X=16
2X=16
X=8

Rule: a ⁃ B = 3A + 4b, known 7 ⁃ x = 45, find X

From a to B = 3A + 4b, there are
7※x=3×7+4x=45
So 21 + 4x = 45
4x=24
x=6