[tex]f(x) = -\frac{1}{2}x^{2}-4x-8 = 0\\\\f(x) = 0\\\\-\frac{1}{2}x^{2}-4x-8 = 0 \ \ /\cdot(-2)\\\\x^{2}+8x+16 = 0\\\\(x+4)^{2} = 0\\\\x+4 = 0\\\\\underline{x_{o} = -4}[/tex]
