after how many terms does an equation have the same five decimals as pi/4?

Question

Nora Al Allaf 2020-9-25

编辑： madhan ravi 2020-9-25

Hi,

so it's given that s = 1 − 1/3 + 1/5 − 1/7 + 1/9 − 1/11 + · · · + (−1)^n / (2n + 1)

what I need to do is, with a while-loop, see after how many terms (n) the equation above gives the same 5 first decimals as pi/4, which is 0.78539...

p = 0;

i = 0;

while 1 == 1 % Infinite loop

p = p + ((-1)^i)/(2*i + 1);

i = i + 1;

if

break

end

I just don't really know what to write in the if statement, tried so much but nothing is really working, would appreciate some help -_-

Answer 1

madhan ravi 2020-9-25

编辑：madhan ravi 2020-9-25

if abs(p - pi/4) < 1e-5

Look through the tag floating-point to know why tolerance is used to compare decimals.