Which of the following function (s) is/are discontinuous at `x = 0?`

Which of the following functions is/are not discontinuous at x=1?

Which of the following functions is/are discontinuous at x=0?f(x)=sin((pi)/(2x)),x!=0 and f(x)=1

Function f(x)=x-|x| is discontinuous at x=0

Which of the following functions f has a removable discontinuity at x=x_(0) ? If the discontinuity is removable, find a function g that agrees with f for xnex_(0) and is continuous on RR . f(x)=(x^(2)-2x-8)/(x+2),x_(0)=-2

Which of the following functions f has a removable discontinuity at x=x_(0) ? If the discontinuity is removable, find a function g that agrees with f for xnex_(0) and is continuous on RR . f(x)=(x^(3)+64)/(x+4),x_(0)=-4

Which of the following functions f has a removable discontinuity at x=x_(0) ? If the discontinuity is removable, find a function g that agrees with f for xnex_(0) and is continuous on RR . f(x)=(3-sqrtx)/(9-x),x_(0)=9

The functions g(x)=x-[x] is discontinuous at x =