Clear Filters
Clear Filters

why "symsum(si​n(k*pi)*k,​0,n)" not equal zero

2 views (last 30 days)
murat
murat on 23 Feb 2014
Answered: Walter Roberson on 23 Feb 2014
why "symsum(sin(k*pi)*k,0,n)" not equal zero?

Answers (3)

Walter Roberson
Walter Roberson on 23 Feb 2014
symsum(sin(k*sym('pi'))*k,0,n)
Remember, "pi" in MATLAB is only a numeric approximation to the transcendental number; you need to use the transcendental number rather than the numeric approximation.

Jan
Jan on 23 Feb 2014
What is n? For e.g. n=0.5 the result is not surprising.

Paul
Paul on 23 Feb 2014
I don't think Matlab recognizes that sin(pi)= 0, therefore it cant simplify further sin(pi*n)*(n/2 + 1/4). Just type sin(pi) and you will see you won't get 0. sind(180) does give 0 but sind doesn't support symbolic variables.

Categories

Find more on Symbolic Math Toolbox in Help Center and File Exchange

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!