Question

Find the x intercept of the graph of the equation -2(x+1)^2 +18

Answer 1

x = - 4, x = 2

Explanation:

To find the x- intercepts equate the equation to zero, that is

- 2(x + 1)² + 18 = 0 ( subtract 18 from both sides )

- 2(x + 1)² = - 18 ( divide both sides by - 2 )

(x + 1)² = 9 ( take the square root of both sides )

x + 1 = ±
`√(9)` = ± 3 ( subtract 1 from both sides )

x = ± 3 - 1

Hence

x = - 3 - 1 = - 4 and x = 3 - 1 = 2

The x- intercepts are x = - 4, x = 2

Answer 2

x=2, -4

Explanation:

The equation is
`y=-2(x+1)^2 +18`. The x-intercept is the point(s) where the function intersects the x axis, so this value can be found by plugging in 0 for y. doing so results in
`0=-2(x+1)^2 +18`. Then, solve for x by moving 18 over, dividing by -2, square rooting both sides, and subtracting 1 to find the value of x.