Question

How do I go about solving this problem in R?

# This is a challenge. Essentially, you will use loops to calculate the # sum of the sequence: 4/1 - 4/3 + 4/5 - 4/7 + 4/9 - 4/11... # Use a for loop and if statements as needed. Store the sum in the # object 'result'. # Once your code works, increase iterations to 10000+ and see what you get. # Hints: # - use an object called "add" that == 1 when you should add a number, # O when you should subtract a number # - You can iterate over a vector of odd numbers, or you can iterate # over i in 1:iterations and turn every i into an odd number, # e.g. 1 -> 1, 2 -> 3, 3 -> 5, 4 -> 7, etc. iterations <- 1000 add <- 1 result <- 0 for(i in _){ # YOUR CODE HERE result

Answer 1

# initiate the result as 0
result <- 0
for(i in 0:1000){
# Create a flag to identify which term to add and which term to subtract
# if iteration number is even then subtract, else add
# subtraction or addition can be done by multiplying the term with -1 or 1 accordingly
flag <- ifelse(i %% 2, -1, 1)
  
# convert the number into odd since the denominator of each term is an odd sequence
odd <- (2*i) + 1
  
# calculate the individual term
temp <- 4 / odd*flag
  
# Take the cumulative sum
result <- result+temp
}

result