Help me!!!! C++ problem?

Question

Please help me!!! I have no idea how to solve all these C++ questions. I tried many ways to solve them. unfortunately there still some error when i run the program.

Here are the questions:

1. Use while loop to show that the following series converges to 2:

1-1/3+1/5-1/7+...

i tried it but the program keep running to infinity and i have to press

ctrl+alt+del to stop it....please help me.

2. Write a program to print out the following pattern by using for loop

1 2 3 4 5 6 7 8 9

1 2 3 4 5 6 7 8

1 2 3 4 5 6 7

1 2 3 4 5 6

1 2 3 4 5

1 2 3 4

1 2 3

1 2

1

I dont know how to do this.

3. Write a program to calculate the mean and variance of ten positive

integers input by the user. The mean, m and variance, v are defined

as follows:

m =∑(xi/n); ===> mean formula

v =∑(xi-m)2/n; ===> variance formula

can use any type of loop structure either while loop, do-while loop or

for loop.

Please...help me to solve it. i need to submit them next week, on August 29.

Answer 1

for your second question, use a nested while-for loop like this

int i=9;

while(i<=1)

{

for(int j=1;j<=i;j++)

{

cout << j << " ";

}

cout << endl;

i--;

}