If a > b > 0, C

If a > b > 0, C

a>b>0
-c>-d>0
-CA > - DB > 0 divided by CD
-a/d>-b/c>0
a/d

-What is the third root of 32

On the inequality ax ^ 2 + 2x + 2A > = 0 of X, where x belongs to [1,3] constant, we can find the range of real number a

Let f (x) = ax ^ 2 + 2x + 2A
(1) When a = 0
F (x) = 2x holds when x belongs to [1,3] greater than zero
(2) When a > 0
Axis of symmetry x = - 1 / A0
Heng was established
(3)a0
∴f(1)≥0,f(3)≥0
-6/11≤a

If the expansion of (x2 + mx-8) (x2-3x + n) does not contain terms x2 and X3, the values of M and N are obtained

The original formula is X4 + (M-3) X3 + (n-3m-8) x2 + (Mn + 24) x-8n. According to the expansion without x2 and X3 terms, m − 3 = 0n − 3M − 8 = 0, the solution is m = 3N = 17

Three fourths plus six thirteenth plus seven thirteenth minus one fourth

3/4+6/13+7/13-1/4
=3/4+（6/13+7/13）-1/4
=3/4+1-1/4
=3/4-1/4+1
=2/4+1
=1/2+1
=3/2

How to find the integral of LNX

With the method of integration by parts,
Let u = LNX, V '= 1,
u'=1/x,v=x,
Original formula = x * LNX - ∫ (1 / x) * xdx
=xlnx-x+C.

On the equation x ^ 2-ax + 4 = 0 of X has a solution on [- 1,1] to find the range of real number a

When there is a solution, substitute f (1) * f (- 1)

How to write 24 times 12 vertical calculation
There's a vertical calculation of 44 times 21

This is the answer
44 24
X 21 X 12
______ ____
44 48
88 24
______ ____
924 288

Why is the definition of function limit required to be centered neighborhood
Such as the title
Request 0

Because x → XO and X →∞ are two processes, X → XO denotes the process of infinite approaching from X to XO, but they are not equal. In "Let f (x) have a definition in a detrended neighborhood of point XO", 1. Embody x → XO, but they are not equal; 2. Make the definition of limit more extensive, even if f (x) has no meaning at XO

2x-3y-8=0,5y-7x-5=0

From 2x-3y-8 = 0
Y = (2x-8) / 3
Substitute it into 5y-7x-5 = 0
5 (2x-8) / 3-7x = 5
Multiply left and right by 3 at the same time
We get 10x-40-21x = 15
x=-5
Substituting x = - 5 into 2x-3y-8 = 0
-10-3y-8=0
y=-6
So x = - 5, y = - 6