Find the vertex of the parabola whose equation is y = -2x2 + 8x - 5

Question

anonymous · Answer

what is the algebraic formula for finding the vertex?

anonymous · Answer

(2, 3)
(2, 19)
(2, 27)

campbell_st · Answer

the vertex of a parabola lies in the line of symmetry

for a parabola in the form $$y = ax^2 + bx + c$$

the line of symmetry is 

$$x = \frac{-b}{2a} $$

in your question a = -2 and b = 8

substitute them to find the line of symmetry. 

When you have the value (of x) for the line of symmetry substitute it into the orginal 
equation to get the vertex

hope this helps

campbell_st · Answer

oops should read substitute x to get the y value of the vertex