Input positive integer n, calculate the sum of the first n terms of 1-1 / 3 + 1 / 5-1 / 7 +. Use C language program to solve

Input positive integer n, calculate the sum of the first n terms of 1-1 / 3 + 1 / 5-1 / 7 +. Use C language program to solve

#include
main( )
{
int denominator ,flag,i,n;
double item,sum;
printf(“Enter n:”);
scanf(“%d”,&n);
denominator = 1;
flag=1;
sum = 0
for(i = 1; i

15 1 / 2-5 / 12 11-6 / 3 2 formula process

15 1-5-12 11-6 2-3
= 6-5 of 15 and 12, 11-6 of 12 and 8 of 12
= 7 of 9 and 12-6 and 8 of 12
= 2 and 11 / 12

4 and 3 / 2-1 and 12 / 11-4 / 3 formula process

4 + 2 / 3-1 + 11 / 12-3 / 4
=14 / 3-23 / 12-3 / 4
=56 / 12-23 / 12-9 / 12 (56 / 12 is 14 * 4 / 3 * 4, and so on)
=(56-23-9)/12
=24 / 12 (simplify)
=2

Combining 2 / 3 × 4 / 3 = 1 / 2,5 / 12 + 1 / 2 = 11 / 12, the formula is ()

5 / 12 + 2 / 3 × 3 / 4 = 11 / 12

Given f (x) = 2 + log3x, X ∈ [1 / 81,9] find the maximum and minimum value of the function y = [f (x)] ^ 2 + F (x ^ 2)

Let: log (3) [x] = t, then: F (X & # 178;) = 2 + log (3) [x & # 178;], X & # 178; ∈ [1 / 81,9], that is: the definition field of function y = [f (x)] &# 178; + F (X & # 178;) is: X ∈ [1 / 9,3]. In this case, y = (T + 2) &# 178; + 2 + 2T = (T + 3) &# 178; - 3, where t ∈ [- 2,1] is combined with quadratic function y = t

1. Is the derivative of a monotone accessible function still monotone? Verification! 2. Prove that the function y = x & # 178; + 3x + 2 is Lagrangian in any interval [A.B]
2. Prove that the function y = x & # 178; + 3x + 2 is 1 / 2 (a + b) by using Lagrange theorem in any interval [A.B]

The derivative of a monotone function is not necessarily monotone, for example, y = X3 over the domain R
Lagrange theorem ((B2 + 3b) - (A2 + 3a)) / (B-A) = B + A + 3 = y '(x) x exists between a and B, y' (x) = 2x + 3, x = 1 / 2 (a + b)
What do you mean by T? Is that x

The sum of the numerator and denominator of a fraction is 43. If 16 is added to the numerator and denominator at the same time, what is the original number of two-thirds

Let the numerator be x and the denominator be y,
Then x + y = 43
(x+16)/(y+16)=2/3
x=14 y=29
The original number is 14 / 29

Find the general solution of the following differential equation (x ^ 2) * y '' - 2XY '- (y') ^ 2 = 0

Let u = y '
x^2*U'-2xU-U^2=0
The above is a simple first order differential equation, you can solve it yourself

4 / 3, 1, 10 / 11, 13 / 15, 16 / 19. Are a series of regular numbers. What is the ninth number in this series

4/3,1,10/11,13/15,16/19
Write the second one as 7 / 7, and the rule is obvious
4/3,7/7,10/11,13/15,16/19
The molecular formula of each fraction starts from 4 with a difference of 3, and the denominator starts from 3 with a difference of 4, so the ninth number is 28 / 35

Use the nine numbers 1-9 to write a division where the divisor is two digits
The number can not be repeated

4396÷28＝157
5346÷18＝297
5346÷27＝198
5796÷12＝483
5796÷42＝138
7254÷39＝186
7632÷48＝159