For #11-12, determine whether the given function is continuous as the specified value of x. Remember to use ALL three tests to justify your answer. 11) Determine whether f(x) is continuous at x = -1. x + x x+1 x 6 13) Determine whether the functions below are continuous or discontinuous. If there exists a discontinuity at any point, identify the discontinuity as removable or non- removable. (a) f (x) =- x-9 x' - 7x -30 (b) f (x) =2x+1 x' +6x+5 For 5-6 find the values of a and b to make the function continuous for all x's 3x + 7 x5-2 4 sin x 5 . f (x ) = ax + b -2