Print out all the Narcissus numbers in the range of 100-999 (the sum of the cubes of a three digit number equals itself), for example, 153 = 1 ^ 3 + 5 ^ 3 + 3 ^ 3

Print out all the Narcissus numbers in the range of 100-999 (the sum of the cubes of a three digit number equals itself), for example, 153 = 1 ^ 3 + 5 ^ 3 + 3 ^ 3

The key to this problem is how to decompose the three digits (set as s)? Take 153 as an example, 153 / 100 = 1 is assigned to a (in C + +, it's integer division) 153% 15 = 3 is assigned to B (in C + +, it's remainder operation) (153 - a × 100) / 10 = 5 is assigned to C, then all the digits are separated

It is known that the speed ratio of the bus to the truck is 3:2. How many hours does it take for the bus to complete the whole journey?

Speed sum: 1 divided by 6 = 1 / 6
3+2=5
Bus speed: 1 / 6 by 3 / 5 = 1 / 10
Bus time: 1 divided by 1 / 10 = 10 (hours)
Can you understand that?

How to find the maximum value of the square of cube-3x of function y = 2x in the interval [- 1,4]?

y'=6x²-6x=6x(x-1)
When - 1 ≤ x ≤ 0, y '≥ 0; when 0

If (3x + y + 6) ^ 2 + | x + y + 2 | = 0, then x=

Because (3x + y + 6) ^ 2 and | x + y + 2 | are both nonnegative numbers
So if (3x + y + 6) ^ 2 + | x + y + 2 | = 0
There must be
3x + y + 6 = 0 and X + y + 2 = 0
therefore
2x=（3x+y+6)-(x+y+2)=-4
So x = - 2

The volume of a cone is 12.56 cubic decimeters, the circumference of its bottom is 6.28, and what is the height of a cylinder?

Bottom circumference = 2 π r = 6.28
R = 1 decimeter
Bottom area = π R ^ 2 = 3.14 cubic decimeter
Cone volume = 1 / 3 x bottom area x H = 12.56
H = 12 decimeters

Let a, B, C, d be positive integers, and A5 = B4, C3 = D2, C-A = 19, then find the value of d-b

A = b4a4 = (b2a2) & nbsp; 2 is obtained from A5 = B4, C = d2c2 = (DC) 2 is obtained from C3 = D2, and (DC) 2 - (b2a2) & nbsp; 2 = 19, (DC + b2a2) (dc-b2a2) = 19 is obtained from C-A = 19

If the solution sets of inequality (A-1) x ＜ (a + 5) × (A-1) and 2x + 4 about X are the same, the value of a is obtained
The answer is "according to the meaning of A-1 < 0" why?

It is said in the title that the solution set must be the same as that of 2x + 4 ＞ 0
From the meaning of the title
A-1 < 0, that is, a < 1
(a-1)x＜(a+5)(a-1),①
It can be reduced to x > A + 5
From 2x + 4 > 0, ②
There is x ＞ - 2
In order to make the solution sets of the two inequalities identical, it is necessary to satisfy the following conditions
a+5=－2
∴a=-7

Counting from 90 to 100 is a total of 10 numbers right or wrong

It's wrong. It's like 11 numbers from 0 to 10

Given that the square of 3 (X-2) and 4 | Y-3 | are opposite to each other, find the value of XY + 1

9 (X-2) & sup2; + 4 Y-3 = 0
So X-2 = 0, Y-3 = 0, x = 2, y = 3
So XY + 1 = 6 + 1 = 7

100 + 99 + 98.61 + 60 summation formula

Arithmetic sequence formula:
(first item + last item) × number of items / 2
100+99+98.61+60
=(100+60）×41/2
=3280