theorem :: DIFF_3:85

for x0, x1 being Real
for f being Function of REAL,REAL st ( for x being Real holds f . x = (cot (#) cos) . x ) & x0 in dom cot & x1 in dom cot holds
[!f,x0,x1!] = ((((1 / (sin x0)) - (sin x0)) - (1 / (sin x1))) + (sin x1)) / (x0 - x1)