MATLAB: Determine Expression

doit4mehomeworkno attemptusing loops and long format

Write a program (using a loop) the dertimes the expression: sqrt 12 Sigma (m on top) (n=0 on bottom) ((-1/3)^n) / (2*n+1) Run the program with m=5 m=10 and m=20. Compare the results with pi (Use Long format).
this is what I have done
format long 
S=0 m=input('Input a value for m=') 
    for n=0:m S(1:m)=sqrt(12)*(S+((-1/3)^n)/(2*n+1))
end
not sure if this is right
run program for m=5 m=10 m= 20
my results m =
     5s =
Columns 1 through 4
   3.464101615137754   3.464101615137754   3.464101615137754   3.464101615137754Column 5
   3.464101615137754s =
Columns 1 through 4
11.615099820540248  11.615099820540248  11.615099820540248  11.615099820540248
Column 5
11.615099820540248
s =
Columns 1 through 4
40.312866084211663  40.312866084211663  40.312866084211663  40.312866084211663
Column 5
40.312866084211663
s =
1.0e+002 *
Columns 1 through 4
   1.396295359331753   1.396295359331753   1.396295359331753   1.396295359331753Column 5
   1.396295359331753s =
1.0e+002 *
Columns 1 through 4
   4.836956528011152   4.836956528011152   4.836956528011152   4.836956528011152Column 5
   4.836956528011152s =
1.0e+003 *
Columns 1 through 4
   1.675569596143254   1.675569596143254   1.675569596143254   1.675569596143254Column 5
   1.675569596143254

Best Answer

the multiplication of sqrt(12) should occur outside the loop. Also do not include S in the summation:
for n = 0:m
s(n+1) = (-1/3)^n/(2*n+1);
end
now you have a vector of values you can sum & multiply by sqrt(12)
Related Question