I can't make up my mind

lim                sqrt ( x^2 + 12x + 36)

x → - 6         _________________

                        x + 6

lim                 sqrt [ (x + 6)^2 ]               l  x + 6 l

x → - 6        ______________    =    _________

                         x + 6                               x + 6

  {  Remember that    sqrt (a^2)  =    l a  l      }

Note  that this limit does not exist as   x → - 6

The numerator will be positive approaching from the left side but the denominator will be negative

So....the result will be negative

The numerator and denominator will be positive approaching from the right side

So.....the result will be positive

See the graph, here  :  https://www.desmos.com/calculator/miohj798g0