How can I get a right solution?

From the euqation expression,b is equal to c and both are equal to zero.However,the simulation result is inverse! I guess that is due to the numerical precision of "double".

What should I do to get right solution？

Thanks!

a = exp(-1i*2*pi/491520*8*10000)

a = 0.5211 - 0.8535i

b = 0.4*a-(a-0.6*a)

ans = -2.7756e-17

c = 0.5*a-(a-0.5*a)

ans = 0

Answer 1

[Image Analyst]

If 10^-17 is not close enough for zero, what precision do you need?

See the FAQ:

https://matlab.fandom.com/wiki/FAQ#Why_is_0.3_-_0.2_-_0.1_(or_similar)_not_equal_to_zero?

Maybe you should try the Symbolic Toolbox.