Question

Find the vertex of this parabola y=-5x^2-10x-15

Answer 1

vertex = (- 1, - 10 )

Explanation:

given the equation of a parabola in standard form

y = ax² + bx + c : a ≠ 0

Then the x-coordinate of the vertex is

`x_(vertex)` = -
`(b)/(2a)`

y = - 5x² - 10x - 15 is in standard form

with a = - 5, b = - 10 and c = - 15, hence

`x_(vertex)` = -
`(-10)/(-10)` = - 1

substitute x = - 1 into the equation for y

y = - 5(- 1)² - 10(- 1) - 15 = - 5 + 10 - 15 = - 10

vertex = (- 1, - 10 )