[tex]y = 2x^{2}+x - 1\\\\a = 2, \ b = 1, \ c = -1\\\\\Delta = b^{2}-4ac = 1^{2} - 4\cdot2\cdot(-1) = 1 + 8 = 9\\\\\sqrt{\Delta} = \sqrt{9} = 3\\\\x_1 = \frac{-b-\sqrt{\Delta}}{2a} = \frac{-1-3}{2\cdot2} = \frac{-4}{4} = -1\\\\x_2 = \frac{-b+\sqrt{\Delta}}{2a} = \frac{-1+3}{4} = \frac{2}{4} = \frac{1}{2}[/tex]
[tex]W = (p, q)\\\\p = \frac{-b}{2a} = \frac{-1}{2\cdot2} = -\frac{1}{4}\\\\q = \frac{-\Delta}{4a} = \frac{-9}{4\cdot2} = -\frac{9}{8}\\\\W = (-\frac{1}{4}, \ -\frac{9}{8})[/tex]
