Find all points of discontinuity of f, where f is defined by`f(x)={{:(x/(|x|), ifx<0),( 1, ifxgeq0):}`

Find all points of discontinuity of f, where f is defined by f(x)={{:((|x|)/x , ifx!=0),( 0, ifx=0):}

Find all points of discontinuity of f, where f is defined by f(x)={{:((x)/(|x|)," if "x lt0),(-1," if "x ge 0):}

Find all points of discontinuity of f, where f is defined by f(x)={{:((x)/(|x|)," if "x lt0),(-1," if "x ge 0):}

Find all points of discontinuity of f, where f is defined by f(x)={{:(x^(10)-1, ifxlt=1),(x^2, ifx >1):}

Find all points of discontinuity of f,where fis defined by xf(x)={(x)/(|x|), if x =0

Find all points of discontinuity of f, where f is defined by f(x)={{:(|x|+3," if "x le -3),(-2x," if "-3 ltx lt 3),(6x+2," if "x ge 3):} .