# 有向數及數線 | Directed Numbers and Number Line

#### 影片內容：

00:05 – 負數 | negative numbers
01:35 – 有向數 | directed numbers
02:54 – 數線 | number line

Cindy has some cookies. The cookies can be divided equally into 16groups, 24groups or 40groups. Find the minimum number of cookies that Cindy has.

Excuse me, may I ask why 0!=1? Thank you.

Excuse me, may I ask why 0!=1?

If there is a tank of length, width, height of 40x10x30 respectively, and there are 8L of water in the tank. Then put a prism of base area 80cm square, height 60cm.The base of the prism touch the bottom of the tank.
Will the water overflowing？？？

the capacity of the tank: 40x10x30=12000ml=12L,
the volume of prism: 80x60x1/3=1600ml=1.6L
the capacity of the tank > the volume of prism+8L
the water won’t overflowing

Why (-2)^0.1 =1.01931714 + 0.331196214 i ?

Is π digits random? (which means each digit appears very close to 10% of the time or not)

https://blogs.sas.com/content/iml/2015/03/12/digits-of-pi.html

how do i rationalise the denominator

Haha 你竟然知道呢度可以用 LaTeX。返返你嘅問題：

New identity web

Haha a little surprise to the old IDENTITY users. Which one do you like better 🙂 ?

The new one of course!

Is 0 a directed number?

Short answer: I don’t think there’s a clear definition on that.

In fact, directed number is not a very rigorous mathematical definition. It’s just a fancy term to emphasize a number can be positive or negative. In that sense, arguing whether 0 is a directed number may not be very meaningful. After all, +0 = -0 = 0.

x(x-2)+A(x-1)≡x^2+B find the value of A and B

I don’t know how to do this question

is it a =2 b=-2

You’re right. A = 2 and B = -2. Well done!

LHS=x(x-2)+A(x-1)
=x^(2)-2x+Ax-A
=x^(2)+(-2+A)x-A

RHS=x^(2)+B
-2+A=0
A=2
-2=B

Anyone could explain the Mandelbrot Set?