Write a mobile app (using TouchDevelop) that calculates 

the sum (which computes e×) of n + 1 terms as

sum =  1 +  x/ 1!   + /2!  + / 3! +  /4!  + …

Values x and n should be read (prompted to enter). Calculate each sequential term base on the previous one to get the best calculation performance (so, the next one = the previous term * (x / i) where i the current control variable – index). Don’t use the math function. Use only one loop. The output should be in the table format as follows (remember to use the reverse wall order shown in class):

x = ?, n = ? 

iteration #   termValue  sum

…

Example:

x = 1,  n = 2

iteration #   termValue  sum

1                     1                 2

2                     0.5              2.5

e× = 2.71828…, where x = 1

Each row corresponds to values in each iteration except the last row which should give the final result in the text box (see p.38 ch3 of our text [3] and also the last exercise in class). A very last line of the output should give the return value of e× from the formula exp(x : Number) : Number (see p.186 of our text).

Test for x = 1, n = 5 and n = 10 – the expected result should be better for n = 10 and you will expect the sum around 2.71828…. Next test for  x = 2, n = 5, and n = 10.