Step-by-step explanation:
Given equation of parabola is
[tex]y =2 x^2 + 14x +11[/tex]
[tex]\Leftrightarrow y =2(x^2 + 7x+\frac {11}{2})[/tex]
[tex]\Leftrightarrow y =2(x^2 + 2\times \frac{ 7}{2}x+\frac{49}{4}-\frac{49}{4}+\frac {11}{2})[/tex]
[tex]\Leftrightarrow y =2[(x + \frac{ 7}{2})^2-\frac{27}{4})][/tex]
[tex]\Leftrightarrow y =2(x + \frac{ 7}{2})^2-\frac{27}{2}[/tex]
[tex]\Leftrightarrow y+\frac{27}{2} =2(x + \frac{ 7}{2})^2[/tex]
Therefore the vertex of the parabola is [tex](-\frac{7}{2},-\frac{27}{2})[/tex] [tex]=(-3\frac{1}{2},-13\frac{1}{2})[/tex]