Proof: 1 / (1 + 1)! + 2 / (2 + 1)! + +n/(n+1)=1-1/(n+1)! Verification: 1 / (1 + 1)! + 2 / (2 + 1)! + +n/(n+1)=1-1/(n+1)!

Using mathematical induction
(1) When n = 1, 1 / (1 + 1)! = 1 / 2 = 1-1 / (1 + 1)!
(2) Suppose that when n = k, the equation holds, that is, 1 / (1 + 1)! + 2 / (2 + 1)! + +k/(k+1)!=1-1/(k+1)!
So, when n = K + 1,
1/(1+1)!+2/(2+1)!+… +k(k+1)!+(k+1)/(k+2)!
=1-1/(k+1)!+(k+1)/(k+2)!
=1-(k+2)/(k+2)!+(k+1)/(k+2)!
=1-1/(k+2)!
So when n = K + 1, the original equation still holds
According to (1) (2), the original equation holds

Factorial in Mathematics For example, if 3! = 1 × 2 × 3, = 1 × 2 × 3 × 4, = 1 × 2 × 3 × 4 × 5, etc., imagine that the quotient of 36! Divided by 35! Is ()

Thirty-six

For any positive integer n, define "double factorial n!" as follows For any positive integer n, define "double factorial n!" as follows: When n is even, = n · (n-2) · (n-4) 6·4·2 When n is odd, = n · (n-2) · (n-4) 5·3·1 There are four propositions as follows: (1) (2007!) · (2006!) = 2007! 2）2006!=2·1003! (3) 2006! Is 0 (4) 2007! Is 5 The correct propositions are

1) 2007! * 2006! = 2007 * 2005 * 2003... 1 * 2006 * 2004.. 2 = 2007! 2) 2006! = 2006 * 2004 *... 2 = 2 ^ 1003 * 1003! 3) 10 is an even number 2006! = 2006 * 2004 * 10.. 2 so the bit is 04) 2007! Is a multiple of 5 and because it is not multiplied by an even number, the number is 5, so 134 is correct

Don't know what "factorial" is? For example, one number is the factorial of another number!

Factorial is a mathematical term. Suppose n is a positive integer, the factorial of n is expressed as n! = 1 * 2 * *n

A mathematical problem about factorial A carpenter has three identical hammers, five different screwdrivers, two identical mallets, two different saws and a tape measure. He wants to put these tools on the shelf. If the first and last tools must be mallets, the hammers cannot be put together. How many methods are there? Except for the condition that "hammers can't be put together", the formula I can list is: (13-2)! / 3!

If only three hammers are considered together, there are nine kinds
9x8!=362880
（13－2）!／3!-9x8!=6289920
The answer is smaller than the one you gave
But (13-2)! / 3! - 9x8! / 72 = 664770 doesn't make sense

On factorial How many seven-digit telephone numbers are there for any one area code if the numbers 0 or 1 can not be used as the first digit of a seven digit phone number?

No factorial The first digit can't use 0 or 1, so there are 8 combinations. The last 6 digits have 10 combinations, which is 8 * 10 ^ 6 = 8000000

On the mathematical problems of factorials, The given condition is: super3! = 1! * 2! * 3! Ask Super 5! Divide by The answer is 48. How?

super5!/6!
=1!*2!*3!*4!*5!/6!
=1!*2!*3!*4!*5!/(6*5!)
=1!*2!*3!*4!/6
=1!*2!*4!
=4*3*2*2=48

The factorial number of 1 plus the factorial of 2 plus 3 has been added to the factorial of 2008? emergency

Starting with the factorial of 5, their single digits are all 0! (because 2 * 5 = 10)
The single digit of 1! + 2! + 3! + 4! Is 1 + 2 + 6 + 4 = 13
So the factorial of 1 plus the factorial of 2 plus 3 has been added to the factorial of 2008 with the single digits of 3
Do you understand? Give me a hard score

What does the mathematical △ sign mean?

Represents the difference, that is, the difference between the two variables mentioned above

The meaning of mathematical symbols Who knows the meaning of these symbols

∫: indefinite integral
∮: total integral
Σ: Sum
Π: quadrature
∝: the function before and after is in direct proportion
Infinity: infinity or infinitesimal
Of (a number belongs to a set)
∩: intersection of two sets (common part)
∪: Union of two sets (all numbers in two sets)
≡: equal to
⊙: circle (for example, ⊙ O means circle O)
≮≠: not less than and not greater than

Proof: 1 / (1 + 1)! + 2 / (2 + 1)! + +n/(n+1)=1-1/(n+1)! Verification: 1 / (1 + 1)! + 2 / (2 + 1)! + +n/(n+1)=1-1/(n+1)!