I am not getting exact value when I substitute the integer in a trignometric function

syms L

F=0.65-0.75/(1+L^2)-0.65*atan(1/L);

L=0.1;

subs(F);

i am getting answer as

ans =

- (13*atan(10))/20 - 187/2020

where i am expecting answer as -0.18819

[DGM]

I'm not sure what's going on here. Since 0.1 isn't an integer, what integer are you referring to? That expression is the exact value. Something like -0.18819 is a floating point approximation. That said, I don't know where you're getting that number. Is it because you're substituting something other than 0.1?

syms L
F = 0.65-0.75./(1+L.^2)-0.65*atan(1./L);
r = subs(F,L,0.1)

r = 

double(r)

ans = -1.0488

Lq = vpasolve(F == -0.18819,L)

Lq = 

1.0700201776695503481435939309154