Question

What is the vertex of g(x)=8x^2-64x

Answer 1

The correct answer is
`\mathrm{Parabola\:vertex\:given}\:y=8x^2-64x:\quad \mathrm{Minimum}\space\left(4,\:-128\right)`

Steps:

`\mathrm{For\:a\:parabola}\:ax^2+bx+c\:\mathrm{the\:vertex's\:x\:equals}\:(-b)/(2a) </p><p>\:a=8,\:b=-64</p><p>x=(-\left(-64\right))/(2\cdot \:8)`

`\mathrm{Simplify}</p><p>x=4`

`\mathrm{Plug\:in}\:x=4\:\mathrm{to\:find\:the\:y\:value}</p><p>y=8\cdot \:4^2-64\cdot \:4`

`\mathrm{Simplify}</p><p>y=-128`

`\mathrm{Therefore\:the\:parabola\:vertex\:is}</p><p>\left(4,\:-128\right)`

`\mathrm{Minimum}\space\left(4,\:-128\right)`