Given the function y = x + 2 (1) when x takes what value, the value of Y is - 5?; (2) when x takes what value, the value of function is positive?; (3) find the function image and X

Given the function y = x + 2 (1) when x takes what value, the value of Y is - 5?; (2) when x takes what value, the value of function is positive?; (3) find the function image and X

1、
y=x+2=-5
x=-7
2、
y=x+2>0
x>-2
3、
Is it the point of intersection with the x-axis?
X axis y = 0
So y = x + 2 = 0
x=-2
So the intersection is (- 2,0)

Where is the Three Gorges

Qutang gorge, Wu Gorge and Xiling Gorge are also referred to as the Three Gorges hydropower station above

On the operation of higher order infinitesimal
Please write down the rigorous calculation process, I know the result
o(2x^2)
o(x^2) - o(x^3)
x *o(x^2)

this is a dog is black and white

How many minutes and seconds is 3 of 8

22 minutes 30 seconds

What is 29 * 28 of 29 + 27 * 28 of 27?

Two out of 28 is one out of 14

An arithmetic sequence {AK} has n items, n is odd, the sum of all odd items is 132, and the sum of all even items is 120
1, find n
2, if an = 2, find the general term AK

An arithmetic sequence {AK} has n items, n is odd, the sum of all odd items is 132, and the sum of all even items is 120. 1, find n; 2, if a &; = 2, find the general term AK ∵ n is odd, there are: A &; + a &; + A &; +. + A &; n &; = 132. (1) a &; + A &; + A &; +. A &

Change a 100 yuan note into 1 yuan, 2 yuan, 5 yuan, 10 yuan notes. At least one note of each kind. How many ways do you have

1、2、2、5、10、10、10、10、10、10、10、10、101、1、2、2、2、2、5、5、10、10、10、10、10、10、10、10、1、1、1,2、5、10、10、10、10、10、10、10、10、101、1、1、1、2、2、2、5、5、10、10、10、10、10、10...

Find the rule: 2 / 1,0.4,37.5%, 4 / 11,5 / 14, () (fill in the fraction), () (fill in the percentage)

A: 6 / 17,35%. Add one to the numerator and three to the denominator

Let a be a real number and f (x) = a-22x + 1 (x ∈ R). If f (x) is an odd function, find the value of A

∵ f (x) = a-22x + 1 (x ∈ R) is an odd function, ∵ f (0) = 0. That is, f (0) = A-22 = a − 1 = 0. The solution is a = 1. That is, the value of a is 1

Integral of 1 / (x ^ 2 * sqrt (x ^ 2 + 1))

Let x = tany, then siny = x / √ (X & # 178; + 1), DX = sec & # 178; YDY
∫dx/[x²√(x²+1)]=∫sec²ydy/(tan²y*secy)
=∫cosydy/sin²y
=∫d(siny)/sin²y
=C-1 / siny (C is the integral constant)
=C-1/[x/√(x²+1)]
=C-√(x²+1)/x.