Find the x-values (if any) at which the function f(x) = x+6 x2+13x+42 is not continuous. Which of the discontinuities are removable? no points of continuity no points of discontinuity x = −6 (removable), x = −7 (not removable) x = −6 (not removable), x = −7 (not removable) x = −6 (not removable), x = −7 (removable)