\[y = \frac{1}{2}x^{2};\ \ y = 3x + 1;\]
\[\frac{1}{2}x^{2} = 3x + 1\ \ \ | \cdot 2\]
\[x^{2} - 6x - 2 = 0\]
\[D_{1} = 9 + 2 = 11 \geq 0\]
\[пересекаются.\]
\[x_{1} = 3 + \sqrt{11};\]
\[y_{1} = 3\left( 3 + \sqrt{11} \right) + 1 =\]
\[= 9 + 3\sqrt{11} + 1 = 10 + 3\sqrt{11};\]
\[x_{2} = 3 - \sqrt{11};\]
\[y_{2} = 3\left( 3 - \sqrt{11} \right) + 1 =\]
\[= 9 - 3\sqrt{11} + 1 = 10 - 3\sqrt{11}.\]
\[Точки\ пересечения:\ \]
\[\left( 3 - \sqrt{11};10 - 3\sqrt{11} \right);\]
\[\left( 3 + \sqrt{11};10 + 3\sqrt{11} \right).\]