(1 + 2 + 3 + 4 + 5 + 6 + 5 + 4 + 3 + 2 + 1) divided by (666666 times 666666)

(1 + 2 + 3 + 4 + 5 + 6 + 5 + 4 + 3 + 2 + 1) divided by (666666 times 666666)

thirty-six

Calculation: (2 √ 6 - 1) / (√ 2 + √ 3 + √ 6)
xiexie

The original formula = (2 √ 6-1) (√ 2 + √ 3 - √ 6) / (√ 2 + √ 3 - √ 6) (√ 2 + √ 3 + √ 6)
=(2√6-1)(√2+√3-√6)/(2+2√6+3-6)
=(2√6-1)(√2+√3-√6)/(2√6-1)
=√2+√3-√6

If the absolute value of (3x-2y) &# 178; + X + 2 = 0, find the integer x & # 179; + Y & # 179; - 1=

If (3x-2y) &# 178; + ｜ x + 2 ｜ = 0
Then (3x-2y) &# 178; = 0, ｜ x + 2 ｜ = 0
∴{3x-2y=0
x+2=0
The solution is: {x = - 2
y= -3
∴ x³+y³-1
=(-2)³＋(-3)³-1
=-8+(-27)-1
=-36

Inverse function of y = x ^ 2-4x (x ≤ 1)

y=(x-2)²-4
(x-2)²=y+4
x

It is known that the function f (x) is an odd function on R. when x ≥ 0, f (x) = x (x + 1). If f (a) = - 2, then the real number a=______ ．

Let x ＜ 0, then - x ＞ 0, so f (- x) = - x (1-x), and f (x) is an odd function, so when x ＜ 0, f (x) = x (1-x), Let f (a) = a (1-A) = - 2, then a2-a-2 = 0, and a = - 1 or a = 2 (rounding off)

Given that the function f (x) = ax △ 2x + 3) satisfies f [f (x)] = x to find the value of A

f(x)=ax/(2x+3)
f[f(x)]=a[ax/(2x+3)]/[2ax/(2x+3)+3]=x
a[ax/(2x+3)]/[2ax/(2x+3)+3]=x
Multiply left by 2x + 3
a^2x/(2ax+6x+9)=x
a^2x=2ax^2+6ax^2+9x
(a^2-9)x=(2a+6)x^2
(a+3)(a-3)x=2(a+3)x^2
(a+3)[(a-3)x-2x^2]=0
This equation is identical because x is not equal to 0
So (A-3) x-2x ^ 2 = 0 is not constant
So a + 3 = 0
a=-3

If a is a symmetric matrix and t is an orthogonal matrix, it is proved that T ^ - 1 * at is a symmetric matrix

T'T=I => T^{-1}=T' => T^{-1}AT=T'AT=(T'AT)'.

Is life plural?

The plural is lives
If there is no plural, life is still used

Calculate the value of 8 ^ 2 / 3 * 16 ^ - 1 / 2 + 10 ^ Lg3 + LG √ (3 / 5) + 1 / 2lg5 / 3

8^2/3*16^(-1/2)+10^lg3+lg√(3/5)+1/2lg5/3
=(2^3)^2/3*(4^2)^(-1/2)+10^lg3+lg√(3/5)+lg√(5/3)
=2^2*4^(-1)+10^lg3+lg√(3/5*5/3)
=4*1/4+10^lg3+lg1
=1+3
=4

A lot of and lots of modify countable nouns or uncountable nouns? What's the difference between so much and them?

A lot of and lots of have the same effect and can be replaced with each other
They can modify both countable and uncountable nouns
So much can only be used to modify uncountable nouns
complete.