Matlab syms variable precision? -

just having issues variable precision in matlab..

i have code:

x = 0.1; syms y; s = solve(x+1==(1+y)/(1-y),y); y = double(s); val = abs(((2^2)*(y^2))/(2*(y-1)^2)) 

but val rounded off. should getting val = 0.0049999 instead getting val = 0.0050.

anyone have idea why?

thanks.

edit: adding code

x = 0.1; syms y; s = solve(x+1==(1+y)/(1-y),y); y = double(s); val = abs(((2^2)*(y^2))/(2*(y-1)^2)) sprintf('%22.20f',val)  i=1:2     val= val+((2^i)*(y^i))/(i*(y-1)^i);     sprintf('%22.20f',val) end 

the first sprintf works , shows correct rounding, second doesnt!!

it has floating-point representation , how matlab displays such numbers readability. if add line end of code:

sprintf('%22.20f',val) 

you'll get:

ans =  0.00499999999999999924 

edit
though technically deals python, this website offers brief , concise overview on limitations of floating-point representations.